Irritable Bowel Syndrome: Clinical Guidelines

List of Abbreviations

VIH – visceral hypersensitivity

GIT – gastrointestinal tract

RCT – randomized controlled trial

SIBO – small intestinal bacterial overgrowth

SSRI – selective serotonin reuptake inhibitor

IBS – irritable bowel syndrome

IBS-D – irritable bowel syndrome with diarrhea

IBS-C – irritable bowel syndrome with constipation

IBS-M – mixed irritable bowel syndrome

Terms and Definitions

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder characterized by abdominal pain related to defecation, changes in stool frequency, and altered stool consistency.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder characterized by abdominal pain related to defecation, changes in stool frequency, and altered stool consistency.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The etiology and pathogenesis of irritable bowel syndrome remain insufficiently studied. It is hypothesized that alterations in the gut microbiota combined with increased permeability of the mucosal-epithelial barrier lead to inflammatory changes in the intestinal wall. Chronic inflammation enhances visceral sensitivity, resulting in hyperactivation of higher nerve centers (primarily the limbic system) with increased efferent innervation of the bowel, impaired gastrointestinal motility, and the development of disease symptoms. Concomitant emotional disorders (anxiety, depression, somatization) contribute to a "vicious circle" in which the patient focuses on somatic symptoms, thereby further amplifying them.

1.3 Epidemiology of the Disease or Condition

IBS affects 10% to 13% of the population. The proportion of individuals experiencing symptoms consistent with IBS is likely higher, but only 25–30% of them seek medical care. The condition is more common in women, and the diagnosis of IBS is most frequently established between the ages of 30 and 50 years. In the majority of IBS patients (13–87%), the disease is comorbid with functional dyspepsia.

Regarding the pediatric population, IBS is reported to be one of the most common forms of functional gastrointestinal disorders in children. For instance, according to a meta-analysis based on epidemiological studies of abdominal pain from 1957 to 2014, IBS was observed in 8.8% of children. Another systematic review and meta-analysis of IBS in children in Asia showed a higher prevalence of 12.4% [97]. Several studies conducted in Greece, Nigeria, South America, and Sri Lanka demonstrated that IBS is the most common disorder among children and adolescents (2.9%, 9.9%, 3.8%–6.4%, and 3.6%–7%, respectively) [98,99,100,101,102,103,104,105].

Many other studies have also reported a high prevalence of IBS in China (13.25%) [106], Nigeria (16%) [107], and Turkey (22.6%) [108]. In contrast, studies conducted in the USA showed lower IBS prevalence rates (2.8% and 5.1%, respectively) [109,110]. A study from the Mediterranean region also reported IBS in 4% of children and adolescents [111, 112].

The incidence of IBS in children peaks during adolescence. The prevalence of IBS in the Russian Federation is up to 14% among junior schoolchildren and up to 35% among adolescents, affecting boys and girls equally [113, 114]. Regarding gender distribution in childhood, IBS is more frequently observed in girls: the female-to-male ratio among pediatric IBS patients is 4:1 [134,135,136].

The presence of IBS is not associated with an increased risk of colorectal cancer or inflammatory bowel disease, nor with increased mortality. Although IBS does not affect mortality, the disease can significantly impair patients' quality of life [1] and leads to substantial direct and indirect costs for its treatment and diagnosis [2].

1.4 Features of Coding the Disease or Condition

K52.3 Indeterminate colitis

K52.9 Noninfective gastroenteritis and colitis, unspecified

K58.0 Irritable bowel syndrome with diarrhea

K58.1 Irritable bowel syndrome with predominant diarrhea

K58.2 Irritable bowel syndrome with predominant constipation

K58.3 Irritable bowel syndrome with mixed features

K58.8 Other or unspecified irritable bowel syndrome

K58.9 Irritable bowel syndrome without diarrhea

K59.1 Functional diarrhea

K59.2 Neurogenic bowel, not elsewhere classified

K59.8 Other specified functional intestinal disorders

K59.9 Functional intestinal disorder, unspecified

1.5 Classification of the disease or condition

Depending on the nature of stool changes, four possible IBS subtypes are distinguished: constipation-predominant IBS, diarrhea-predominant IBS, mixed IBS, and unclassified IBS. This classification is based on stool consistency according to the Bristol Stool Form Scale (Appendix D), which is easily understood by patients and allows rapid identification of the nature of stool disorders.

• IBS with constipation (IBS-C): hard or lumpy stools (Bristol type 1–2) in more than 25% of defecations; loose/watery stools (Bristol type 6–7) in less than 25% of defecations. Alternative diagnostic criterion for this subtype: the patient reports predominantly experiencing constipation (Bristol type 1–2).

• IBS with diarrhea (IBS-D): loose or watery stools (Bristol type 6–7) in more than 25% of defecations; hard or lumpy stools (Bristol type 1–2) in less than 25% of defecations. Alternative diagnostic criterion for this subtype: the patient reports predominantly experiencing diarrhea (Bristol type 6–7).

Mixed IBS (IBS-M): hard or lumpy stools (Bristol type 1–2) in more than 25% of defecations, and loose or watery stools (Bristol type 6–7) in more than 25% of defecations. Alternative diagnostic criterion for this subtype: the patient reports experiencing both constipation (in more than ¼ of all defecations) and diarrhea (in more than ¼ of all defecations), corresponding to Bristol types 1–2 and 6–7, respectively.

• Unclassified IBS (IBS-U): patient symptoms meet the diagnostic criteria for IBS but are insufficient to diagnose the first three subtypes of the disease.

Patients' understanding of the terms "constipation" and "diarrhea" should be carefully assessed. For instance, many IBS patients complaining of diarrhea actually mean frequent defecation while the stool remains formed; patients complaining of "constipation" may report anorectal discomfort during defecation rather than infrequent bowel movements or passage of hard stools.

In childhood, the incidence of intestinal infections is high, and IBS frequently develops as a sequela of acute intestinal infections [134, 135]. Therefore, IBS in children is classified not only by stool consistency but also by the etiological factor:

• post-infectious IBS (PI-IBS) or IBS-like syndrome;

• food intolerance-associated IBS;

• classic stress-induced IBS.

1.6 Clinical presentation of the disease or condition

Symptoms reported by IBS patients can be conditionally divided into three groups:

• intestinal symptoms;

• symptoms related to other parts of the gastrointestinal tract (GIT) (e.g., nausea, heartburn) [3,4];

• extra-gastrointestinal symptoms (dyspareunia, sensation of incomplete bladder emptying, fibromyalgia, migraine) [3].

The presence of symptoms related to other parts of the GIT, as well as extra-gastrointestinal symptoms, makes the diagnosis of a functional disorder more probable.

In addition, IBS patients should be evaluated for the presence of emotional disorders such as anxiety, depression, or hypochondriasis [4,5].

In pediatric patients, intestinal complaints are more characteristic: abdominal pain of varying intensity and inconsistent localization, associated with altered bowel habits; flatulence that worsens throughout the day. Additional criteria in children include a variety of autonomic and neurological complaints [135, 137].

Intestinal symptoms in IBS have a number of specific features.

o Abdominal pain lacks a clear localization, but most frequently occurs in the left lower quadrant. Pain typically intensifies after meals. An important distinguishing feature of abdominal pain in IBS is its absence during nighttime hours [6]. In women, pain intensifies during menstruation [7].

o The sensation of abdominal bloating is less pronounced in the morning, increases throughout the day, and worsens after eating [8].

o Diarrhea usually occurs in the morning after breakfast; stool frequency ranges from 2 to 4 or more times within a short period, often accompanied by urgency and a feeling of incomplete bowel evacuation. Frequently, during the first bowel movement, the stool is more formed than in subsequent ones, when the volume of intestinal contents is reduced but the consistency is looser. Total daily stool weight does not exceed 200 g. Nocturnal diarrhea is absent.

o Constipation may manifest as "sheep-like" hard pellets, pencil-like stools, or cork-like stools (passage of firm, formed stool at the beginning of defecation, followed by mushy or even watery stool). Stools contain no blood or pus, though mucus in the stool is quite commonly observed [9].

The clinical symptoms listed above cannot be considered specific to IBS, as they may also occur in other bowel diseases.

When examining patients with IBS, one's attention is drawn to the discrepancy between the large number of complaints presented, the long history of the disease, and the satisfactory general condition of the patient [9]. In childhood, physical development remains satisfactory even with a long-term course of IBS.

2. Diagnostics, medical indications and contraindications for diagnostic methods

The diagnosis of IBS is established when the patient's complaints meet the Rome IV criteria, organic gastrointestinal diseases are excluded, and "red flag symptoms" are absent.

According to the Rome IV criteria, irritable bowel syndrome (IBS) is defined as a functional bowel disorder manifested by recurrent abdominal pain occurring at least 1 day per week, characterized by the following features (two or more):

1. Related to defecation

2. Associated with a change in stool frequency

3. Associated with a change in stool form

These symptoms must be present for the last 3 months with a total duration of at least 6 months.

As with other functional gastrointestinal disorders, the diagnosis of IBS can be established based on the correspondence of the patient's symptoms to the Rome IV criteria in the absence of organic causes for their occurrence.

The "red flag symptoms" include the symptoms listed below, which may be a manifestation of organic disease and should serve as an indication for in-depth examination.

Complaints and anamnesis:

• weight loss

• onset in elderly age

• nocturnal symptoms

• history of colorectal cancer, celiac disease, ulcerative colitis, and Crohn's disease in relatives

• constant abdominal pain as the sole and leading symptom of gastrointestinal involvement

• progressive course of the disease

Physical examination:

• fever

• changes in internal organs (hepatomegaly, splenomegaly, etc.)

Laboratory parameters:

• decreased hemoglobin level

• leukocytosis

• elevated ESR

• presence of fecal occult blood

• changes in blood chemistry profile

• steatorrhea and polyfecalia [9].

In children, additional "red flag symptoms" may include;

• family history burdened with inflammatory bowel diseases, celiac disease [6];

• arthritis;

• pararectal diseases;

• linear growth deceleration;

• delayed puberty.

The Rome IV criteria note that a number of conditions, including chronic inflammatory bowel diseases, celiac disease, lactose and fructose intolerance, microscopic colitis, etc., can present under the "mask" of IBS; therefore, a limited range of studies may be performed for differential diagnosis. According to the authors, the diagnosis of IBS should be based on four components: medical history, physical examination of the patient,

minimal laboratory tests, and — if clinically indicated — colonoscopy results.

However, this approach is fraught with serious diagnostic errors, since a number of organic diseases, such as chronic inflammatory bowel diseases, microscopic colitis, and even colorectal tumors, can present with the clinical picture of IBS in the absence of "red flag symptoms". Therefore, it is advisable to consider IBS as a diagnosis of exclusion.

2.1 Complaints and Anamnesis

Complaints and medical history typical for patients with IBS are specified in subsection 1.6.

2.2 Physical Examination

Physical examination should be aimed at excluding organic disease and must include examination of the perianal area and digital rectal examination [3]. In children, determining physical development parameters (measuring height, measuring body weight) is mandatory [135].

2.3 Laboratory Diagnostics

For adults — Recommendation Grade – B (Level of Evidence – 3)

For children — Recommendation Grade – C (Level of Evidence – 5)

For adults — Recommendation Grade – B (Level of Evidence – 2)

For children — Recommendation Grade – C (Level of Evidence – 5)

Comments: other confirmatory tests are performed in accordance with clinical guidelines for celiac disease

For adults — Recommendation Grade – B (Level of Evidence – 3)

For children — Recommendation Grade – C (Level of Evidence – 5)

Comment: the choice of tests depends on the clinical situation. IBS may develop within several months after various gastrointestinal infections, including bacterial (e.g., Campylobacter jejuni and Salmonella spp.), viral (Norwalk), and parasitic (cryptosporidia or Giardia [Giardia duodenalis or Giardia lamblia]) infections [116]. It has been shown that, for example, testing for Giardia lamblia (determination of Giardia lamblia antigens in stool samples / molecular biological testing of stool for Giardia lamblia / determination of Giardia lamblia DNA in stool by PCR) combined with stool calprotectin testing increases the sensitivity and specificity of the differential diagnosis of infectious etiology.

For adults — Recommendation Grade – B (Level of Evidence – 3)

For children — Recommendation Grade – C (Level of Evidence – 5)

Comment: When determining the blood level of antibodies to tissue transglutaminase, IgA levels should be assessed, and in case of selective IgA deficiency, IgG levels.

For adults — Recommendation Grade – B (Level of Evidence – 2)

For children — Recommendation Grade – C (Level of Evidence – 5)

• In children with clinical signs of IBS, it is recommended to perform routine tests — urinalysis, coprological examination to exclude organic diseases [135]

GCP CLoE 5Grading of Recommendations Assessment, Development and Evaluation (GRADE) – C (Level of Evidence – 5)

2.4 Instrumental Diagnostics

For adults — Recommendation Grade – B (Level of Evidence – 2)

For children — Recommendation Grade – C (Level of Evidence – 5)

Comments: According to a meta-analysis of 37 studies, 36.7% (95% CI: 24.2%-44.6%) of patients with IBS have SIBO [18, 19]. Since the symptoms of SIBO and IBS largely overlap, SIBO is quite frequently undiagnosed, leading to incorrect management. SIBO is successfully treated in the majority of cases when appropriate therapy is prescribed [20]. Therefore, these tests are recommended for all patients with IBS.

In children, these tests are not routinely performed and may be considered if there are complaints of changes in bowel habits, loss of appetite, and eructation [115].

For adults — Recommendation Grade – B (Level of Evidence – 2)

For children – Level of evidence – C (level of confidence of data – 5)

• In the pediatric population, colonoscopy (colonoscopy with endoscopic small bowel biopsy, colonoscopy with endoscopic large bowel biopsy, pathological-anatomical examination of the small bowel biopsy (surgical) material, pathological-anatomical examination of the large bowel biopsy (surgical) material) to exclude organic diseases, given the available data on its low efficacy in IBS, is recommended to be performed selectively, in the presence of "red flags" requiring the exclusion of organic pathology in order to minimize unwarranted pain [112, 120, 121].

GCP CLoE 5Grading of Recommendations Assessment, Development and Evaluation (GRADE) – C (Level of Evidence – 5)

Comment: A recent systematic review analyzing 8 pediatric studies concluded that fecal calprotectin is a valuable test to exclude IBD and avoid invasive procedures, notably ileocolonoscopy [122]. Children should not undergo ileocolonoscopy if the fecal calprotectin level is < 50 mg/g [123]. In the absence of "red flags" and with fecal calprotectin levels < 250 mcg/g in two separate samples, the presence of IBD is unlikely, and further investigations should not be performed [124]. However, if fecal calprotectin levels are > 250 mcg/g in two separate samples in children with gastrointestinal symptoms suggestive of IBD, this confirms the need for ileocolonoscopy [125].

In childhood, the spectrum of differential diagnosis is somewhat different. The main conditions that require differential diagnosis with IBS include inflammatory bowel disease (Crohn's disease, ulcerative colitis), gastrointestinal food allergy, helminthiasis, pancreatic diseases, celiac disease, and carbohydrate intolerance [134].

2.5 Other Procedures

Additional instrumental and laboratory tests are performed primarily for the purpose of differential diagnosis with a number of diseases.

• Lactase and disaccharidase deficiency, characterized by a link between symptoms and the intake of specific foods. Diagnosis is performed using a hydrogen breath test with lactose or fructose challenge [26];

• Exocrine pancreatic insufficiency [27];

• Radiation (post-radiation) colitis;

• Non-steroidal anti-inflammatory drug-associated colitis;

• Intestinal ischemic disease;

• Colorectal cancer;

• Giardiasis [28];

• Diverticulitis [29, 30];

• Gynecological diseases (endometriosis, inflammatory conditions, ovarian tumors) [31-33].

Rare causes of symptoms characteristic of IBS, primarily the diarrhea-predominant subtype, include Whipple's disease, intestinal amyloidosis, and viral infections of the colon (cytomegalovirus, herpes simplex virus).

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 Basic Principles of Therapy

Establishing a therapeutic alliance between the physician and the patient includes a shared understanding of the nature of the symptoms and diagnosis, agreement on the treatment strategy (drug selection, expectation of treatment onset, patience when switching medications, adaptation to adverse effects), and agreement on the boundaries of therapeutic resources [33].

In childhood, it is also important to pay attention to the child's daily routine (adjusting the daily routine leads to an improvement in the patient's neuropsychiatric status) and the intensity of physical activity. Children and adolescents with IBS should be recommended moderate physical exercise, reduction of psycho-emotional stress, and at least 9–10 hours of sleep per night [135].

3.2 Diet therapy

The diet for a patient with IBS should be selected individually by eliminating foods that aggravate symptoms (elimination diet). Despite conflicting research data on the effect of specific diets, patients with IBS should:

• Eat regularly at designated times, and avoid eating in a hurry or while working.

• Not skip meals or allow long intervals between them.

• Keep a "food diary" to identify foods whose consumption leads to worsening symptoms.

• Patients with diarrhea-predominant and mixed IBS subtypes may be prescribed a gluten-free diet [3].

The efficacy of a diet low in oligo-, di-, monosaccharides (lactose, fructose, fructans, galactans) and polyols (sorbitol, xylitol, mannitol) [34] is questionable [35, 36]. Large-scale studies on the efficacy of increasing physical activity in IBS have not been conducted. Nevertheless, moderate physical exercise (walking, cycling, aerobics) is indicated for patients with IBS, as it leads to a significant reduction in core symptoms [37].

The organization of therapeutic nutrition for patients with irritable bowel syndrome during inpatient treatment in medical organizations is carried out in accordance with the orders of the Russian Ministry of Health dated August 5, 2003, No. 330 "On measures to improve therapeutic nutrition in healthcare institutions of the Russian Federation," dated June 21, 2013, No. 395n "On approval of therapeutic nutrition standards," and dated September 23, 2020, No. 1008n "On approval of the procedure for providing patients with therapeutic nutrition."

3.3 Medical treatment

• Patients with IBS complaining of abdominal pain are recommended the administration of antispasmodics (ATC A03 Drugs for functional gastrointestinal disorders) for pain relief [38].

LoE ALoCD 1Level of evidence – A (level of confidence of data – 1)

Comments: The efficacy of this group of drugs compared to placebo (58% and 46%, respectively) was confirmed in a meta-analysis of 29 studies involving 2,333 patients. The NNT (number needed to treat to achieve a positive outcome in one patient) for antispasmodics was 7 [38].

For example, high efficacy was noted with the use of hyoscine butylbromide, pinaverium bromide, and otilonium bromide (NNT ranging from 3 to 4.5) [39, 40]. According to individual studies, the prescription of certain antispasmodics (ATC A03 Drugs for functional gastrointestinal disorders) (e.g., mebeverine**), along with a reduction in abdominal pain, leads to a significant improvement in the quality of life of patients with various IBS subtypes [41]. Mebeverine** also has a high safety profile and is well-tolerated with long-term use [42]. The spasmolytic action of otilonium bromide is due to its ability to influence calcium ion transport across smooth muscle cell membranes of the digestive tract and to block calcium channels, muscarinic, and tachykinin receptors. In addition, as a tachykinin receptor antagonist, otilonium bromide reduces visceral hypersensitivity [43]. Randomized double-blind placebo-controlled trials have demonstrated the efficacy of otilonium bromide in reducing symptom severity (abdominal pain, bloating) and preventing their recurrence [44].

Overall, according to various authors, the level of studies confirming the efficacy of this drug group ranges from 1 to 3, and the level of clinical practice recommendations ranges from category A to C [45].

Hyoscine butylbromide in children: prescribed from 6 years of age – tablets: 10–20 mg 3–5 times/day. The drug should not be used daily for more than 3 days without consulting a doctor.

Pinaverium bromide is not recommended for use in children under 18 years of age.

Otilonium bromide is contraindicated in children under 18 years of age.

Patients with IBS are recommended to take a combination of an antispasmodic and an antifoaming agent (ATC A03AX58 Alverine in combination with other drugs) – alverine + simethicone (60 mg and 300 mg per capsule, respectively) to reduce abdominal pain severity [46, 115].

For adults – Level of evidence B (level of confidence of data – 2)

For children — Recommendation Grade – C (Level of Evidence – 5)

Comments: The efficacy of the drug in reducing abdominal pain was demonstrated in a randomized, double-blind, controlled study involving 412 patients with IBS who took the drug or placebo 3 times daily for 4 weeks. According to the self-assessment results using the visual analogue scale, the severity of abdominal pain in the main group of patients was significantly lower than in those who received placebo (p=0.047) [46].

In children, alverine + simethicone is approved from the age of 14.

• Adult patients with IBS are recommended the prescription of mebeverine** for pain relief [47]. In children, #mebeverine** can be selectively prescribed if other interventions fail [138].

For adults — Grade of Recommendation B (Level of Evidence – 3).

For children — Grade of Recommendation B (Level of Evidence – 2).

Comments: #Mebeverine** may be used in IBS in children from 6.5 years of age at a dose of 135 mg twice daily for 4 weeks [138].

• Adult patients with IBS are recommended the prescription of antidepressants to reduce abdominal pain [48, 49].

ROB BLOE 1Recommendation grade – B (evidence level – 1).

Comments: in cases where antispasmodics prove ineffective for treating abdominal pain, the prescription of non-selective monoamine reuptake inhibitors (ATC: N06AA) is recommended [50]. This group includes amitriptyline**, an FDA-approved drug for treating depression in adults. In children, the drug is contraindicated under 18 years of age. Indications for which #amitriptyline** may be prescribed off-label include, among others, irritable bowel syndrome [51]. In adults, #amitriptyline** has demonstrated efficacy at a maintenance dose of either 10 mg once daily or 75 mg at bedtime for long-term use [52]. The maintenance dose of 75 mg is achieved by weekly increases of the initial #amitriptyline** dose (25 mg) by 25 mg [53]. Reduction of clinical symptoms may be observed within the first 4 weeks of treatment, but it may take up to 8 weeks to achieve the maximum effect.

Treatment with non-selective monoamine reuptake inhibitors may benefit patients with comorbid neuropathies, fibromyalgia, recurrent migraine, or psychiatric disorders, given their efficacy in these nosological entities [54].

When prescribing this group of drugs, side effects such as dry mouth, drowsiness, and palpitations may occur; however, in placebo-controlled studies, the presence of side effects did not lead to a significantly more frequent need for discontinuation compared to placebo [48].

The establishment of the drug regimen involves individual titration, where each dose increase is carried out once a week and is prompted by insufficient efficacy regarding abdominal pain. The dose can be increased depending on symptom dynamics, although increasing the dose above 50 mg per day may lead to a higher incidence of adverse events. A stable therapeutic effect is achieved within two to four weeks. Afterwards, it is recommended to maintain the dose at which remission is achieved for three months before attempting to discontinue the drug course [55].

In the group of patients receiving selective serotonin reuptake inhibitors (SSRIs), no significant changes in abdominal pain were found compared to baseline [48]. Similar data regarding the low efficacy of SSRIs are also reported in earlier publications [49].

Nevertheless, according to the Rome IV criteria, antidepressants such as #paroxetine** 10–40 mg daily; #sertraline** 25–100 mg daily; #citalopram 10–40 mg daily may be prescribed to reduce abdominal pain [3].

• Children with IBS are recommended to be prescribed antidepressants with caution (strictly under the supervision of a pediatric gastroenterologist and a psychiatrist) in the presence of severe symptoms significantly affecting quality of life and accompanied by significant psychological comorbidities — for pain relief [115].

GCP CLoE 5Grading of Recommendations Assessment, Development and Evaluation (GRADE) – C (Level of Evidence – 5)

Comments: after counseling provided to the patient and their family, #amitriptyline** may be prescribed at 10 mg/day for patients weighing <35 kg or 20 mg/day for patients >35 kg for 4 weeks [139]. It should be noted that further studies on the use of antidepressants in IBS in children are needed.

• Patients with IBS are recommended the prescription of loperamide** for diarrhea management [56, 115].

For adults — Recommendation Grade – B (Level of Evidence – 2)

For children — Recommendation Grade – C (Level of Evidence – 5)

Comments: By reducing the tone and motility of the gastrointestinal smooth muscle, loperamide** improves stool consistency and reduces the frequency of defecation urges; however, it does not significantly affect other IBS symptoms, including abdominal pain. Due to the lack of randomized clinical trials (RCTs) comparing loperamide** with other antidiarrheal agents (ATC A07 Antidiarrheals, intestinal anti-inflammatory/anti-infective agents), the level of evidence for loperamide** efficacy belongs to category 2, and the strength of clinical recommendations is categorized as A by some authors and C by others [39].

Loperamide** is not intended for use in children under 6 years of age. In children with IBS over 6 years of age, selective use of gastrointestinal motility-lowering agents (loperamide**) is possible (not prescribed routinely), while it should be determined whether the diarrhea is linked to a dietary trigger (e.g., lactose, sorbitol); additionally, the presence of ≥3 episodes of loose stools per day in a child for more than two consecutive weeks should be regarded as a red flag symptom requiring investigation for organic pathology.

Adult patients with diarrhea-predominant IBS are recommended the prescription of diosmectite** for diarrhea management [57].

REC CLOE 2 Grade of Recommendation – C (Level of Evidence – 2)

Comments: In a randomized, placebo-controlled study by F.Y. Chang et al. (2007), the efficacy of diosmectite** administered for 8 weeks was evaluated in 104 patients with diarrhea-predominant IBS. Daily intake of the drug (1 sachet 3 times daily) contributed to a significant (compared to baseline and placebo) improvement in the quality of life of IBS patients, as well as a reduction in the intensity of abdominal pain and flatulence [57].

• Patients with diarrhea-predominant IBS sould be prescribed oral #rifaximin at a dose of 400 mg every 12 hours for 10 days to control diarrhea [58].

LoE ALoCD 1Level of evidence – A (level of confidence of data – 1)

Comments: according to a meta-analysis of 18 randomized placebo-controlled trials including 1,803 patients with diarrhea-predominant IBS, a short course of the non-absorbable antibacterial agent #rifaximin effectively relieves diarrhea and helps reduce abdominal bloating in such patients. At the same time, the NNT was found to be 10.2 [58].

In children with IBS, #rifaximin is used at a total daily dose of 600 mg, divided into 3 doses — for a 7-day course (from 7 years of age) [115, 126, 127].

• Patients with constipation-predominant IBS are recommended the prescription of bulk-forming laxatives (ATC: A06AC) for the treatment of constipation [39, 59, 112, 121, 128].

REC BLOE 2 Grade of Recommendation – B (Level of Evidence – 2)

Comments: Drugs of this group increase the volume of intestinal contents and give stool a soft consistency. They do not exert an irritant effect on the bowel, are not absorbed, and do not cause habituation.

For Ispaghula (Plantago ovata) seed husk, the recommended dose is at least 10 g/day. According to a 12-week randomized placebo-controlled study involving 275 patients, the prescription of Ispaghula seed husk at a dose of 10 g/day resulted in a significant reduction in disease symptoms as early as the first month of treatment; whereas the inclusion of bran in the diet (10 g/day) showed alleviation of disease symptoms only by the third month of observation, while the number of patients who dropped out due to increased symptom intensity was significantly higher in the bran-treated group [59].

In general, despite a rather long period of use of dietary fibers in the treatment of IBS, their efficacy remains ambiguous. The administration of psyllium (Plantago ovata) seed husk leads to a significant decrease in the severity of disease symptoms, whereas insoluble dietary fibers (bran) are less effective and may lead to symptom exacerbation [39].

The use of psyllium (Plantago ovata) seed husk is approved in children from 12 years of age.

• Patients with constipation-predominant IBS are recommended to prescribe osmotic laxatives (ATC: A06AD) for the treatment of constipation [60, 61].

GOR CLEL 5Grade of Recommendation – C (Level of Evidence – 5)

Comments: Osmotic laxatives. The most studied agents of this drug group include polyethylene glycol (PEG, macrogol**), lactulose**, and lactitol, which help slow down water absorption and increase the volume of intestinal contents. They are not metabolized in the gastrointestinal tract, do not cause structural changes in the colon or dependence, and help restore the natural urge to defecate. The efficacy of osmotic laxatives has been proven in placebo-controlled studies, including long-term use (12 months) and use in pediatrics. An increase in stool frequency and improvement in stool consistency three months after the start of treatment was noted in 52% of patients with constipation-predominant IBS receiving PEG and in only 11% of patients receiving placebo. International clinical studies have demonstrated the feasibility of long-term PEG use (up to 17 months) [60].

With a course administration of PEG, a carry-over effect was demonstrated—ensuring normal bowel function after drug withdrawal. According to the American College of Gastroenterology (ACG) and the American Society of Colon and Rectal Surgeons (ASCRS), the level of evidence for the efficacy of this drug group is 1; however, the grade of practical recommendations varies from category A (according to ACG) to category B (according to ASCRS).

The use of PEG in children is approved starting from 6 months of age.

Taking into account the significant contribution of the gut microbiota—which promotes fecal mass formation and the production of various metabolites, primarily short-chain fatty acids (SCFAs)—to the regulation of gastrointestinal motility, it is possible to prescribe agents with a complex mechanism of action that have a normalizing effect on both gastrointestinal motility and the composition and functions of the gut microbiota (e.g., lactitol) [61, 62].

• Patients with constipation-predominant IBS are recommended to prescribe stimulant laxatives (ATC: A06AB) for the treatment of constipation [63, 64].

GRC ALEL 2Grade of Recommendations – A (Level of Evidence – 2)

Comments: Medicines of this group stimulate chemoreceptors of the colonic mucosa and enhance its peristalsis. According to a conducted study, the number of spontaneous bowel movements in patients with chronic constipation receiving bisacodyl** increased from 0.9 to 3.4 per week, which was significantly higher than in patients receiving placebo (increase in bowel movements from 1.1 to 1.7 per week) [63].

However, despite the rather high level of efficacy and safety of this group of drugs, most studies conducted to determine these parameters were performed more than 10 years ago and can be assigned to category 2 in terms of the level of evidence. According to ACG data, the grade of practical recommendations is category B, and according to ASCRS data, it is C, which is probably due to the possibility of pain occurring while taking stimulant laxatives [65].

According to the guidelines of the Russian Gastroenterological Association (RGA), the duration of treatment with drugs of this group should not exceed 10–14 days.

In children, the use of bisacodyl** is approved from 10 years of age.

• Adult patients with constipation-predominant IBS are recommended to be prescribed prucalopride (ATC: A06AX05) for the treatment of constipation in the absence of an effect from the aforementioned laxatives [35, 66].

GRC BLEL 1Grade of Recommendations – B (Level of Evidence – 1)

Comments: Prucalopride has been approved since 2009 in European countries for the treatment of chronic constipation in women, including constipation-predominant IBS, when laxatives have failed to provide the proper effect in relieving constipation symptoms [33, 67].

Prucalopride has a positive effect on all symptoms of constipation, including concomitant ones (bloating, abdominal pain), improves quality of life, and provides a lasting effect with long-term use. The drug is distinguished by ease of administration and dosing (1 mg in individuals over 65 years of age or 2 mg in individuals under 65 years of age once daily) and predictability of effect. Side effects of the drug, usually of mild severity (headache, nausea, diarrhea, abdominal pain), are most often noted on the 1st day of treatment, in most cases resolve spontaneously, and do not require discontinuation of the drug. Except for the first day of administration, the tolerability of prucalopride is identical to placebo [66].

The use of prucalopride in children under 18 years of age is not recommended.

• Patients with IBS are recommended to be prescribed strain-specific probiotics (A07FA: Bifidobacterium longum + Enterococcus faecium; A07FA02: Saccharomyces boulardii) to reduce the severity of disease symptoms [68–78].

LoE ALoCD 1Level of evidence – A (level of confidence of data – 1)

Comments: Probiotics are live microorganisms that confer a health benefit on the host when administered in adequate amounts [68].

A recent meta-analysis of 22 randomized placebo-controlled trials involving 3,144 subjects with IBS demonstrated that probiotics reduce the severity of disease symptoms (OR=1.50; 95% CI 1.23–1.83), with the NNT being 5. The efficacy of probiotics in IBS for reducing the severity of abdominal pain (meta-analysis of 18 RCTs involving 2,766 patients, standardized mean difference (SMD) was -0.31; 95% CI from -0.45 to -0.17) and abdominal bloating (meta-analysis of 15 RCTs involving 2,283 patients, SMD=-0.20; 95% CI from -0.38 to -0.01) compared with placebo was highlighted separately [69].

The efficacy of probiotics in IBS depends on the bacterial or fungal strains included in their composition, which have demonstrated their potential at certain doses, release forms, and administration regimens [70]. Probiotic compositions registered in the Russian Federation that have proven their efficacy in IBS in appropriate clinical trials (as medicinal products) are presented in the table below (Table 1) [71–78].

Table 1

Probiotics (medicines – ATC A07FA: Bifidobacterium longum + Enterococcus faecium; A07FA02: Saccharomyces boulardii) effective for the treatment of IBS in adults

Note: PI-IBS – post-infectious IBS; IBS/FD – IBS combined with functional dyspepsia; Russian Ministry of Health CG – IBS diagnosis established according to the Clinical Guidelines of the Russian Ministry of Health

• Patients with IBS are recommended to be prescribed trimebutine to reduce abdominal pain and normalize stool frequency and consistency [79–82].

GRC CLEL 5Grade of Recommendations – C (Level of Evidence – 5)

Comments: In addition to drugs that affect a specific symptom of the disease—abdominal pain, diarrhea, or constipation—medicines are also used in the treatment of IBS patients which, taking into account their mechanism of action, help both reduce abdominal pain and normalize stool frequency and consistency.

Thus, for the treatment of abdominal pain and stool disorders in patients suffering from IBS, synthetic anticholinergics—tersrtiary amine esters that normalize intestinal motor activity and, in addition, increase the pain threshold by acting on glutamate receptors in the synapses of the dorsal horns of the spinal cord—are successfully used [79].

The drug from this group, trimebutine, is safe for long-term use and is also effective in treating comorbid functional disorders (specifically, the combination of functional dyspepsia and IBS [80]). The level of evidence for the efficacy of trimebutine corresponds to category 2, and the grade of recommendations is category B.

According to clinical trial results, treatment regimens incorporating trimebutine demonstrate greater efficacy compared to regimens prescribing antispasmodics in reducing the severity of IBS and functional dyspepsia symptoms [81], with the exception of constipation and altered stool consistency (hard stool) – for these symptoms, the efficacy of trimebutine-containing regimens was comparable to that of regimens including antispasmodics [82].

Trimebutine is approved for use in children in the form of tablets, powder, or granules for the preparation of an oral suspension: ages 3 to 5 years, 25 mg 3 times/day; ages 5 to 12 years, 50 mg 3 times/day; age 12 and older, 100–200 mg 3 times/day. The course of treatment is 1 month.

• For patients with IBS, it is recommended to include a dietary supplement containing peppermint oil, ginger oil, and olive oil in the treatment regimen to reduce the severity of disease symptoms [83].

GR BLE 2Grade of recommendation – B (Level of evidence – 2)

Comments: A double-blind, placebo-controlled, randomized trial showed that a dietary supplement containing peppermint oil, ginger oil, and olive oil significantly outperforms placebo in reducing the severity of disease symptoms in patients with IBS when included in the treatment regimen (p = 0.009). The daily dose of this supplement contained standardized amounts of gingerol (7 mg), menthol (80 mg), and D-limonene (5 mg).

• For adult patients with IBS, it is recommended to prescribe Kolofort to reduce abdominal pain and normalize stool frequency and consistency [84–86].

GR CLE 2Grade of recommendation – C (Level of evidence – 2)

Comments: This drug has spasmolytic, anti-inflammatory, and anxiolytic effects. The efficacy of the drug has been proven in randomized placebo-controlled trials [84–86]. The course of treatment is 1–3 months; if necessary, the course of treatment can be extended up to 6 months and/or repeated after 1–2 months. The drug is used both as monotherapy and in combination with antispasmodics and other medications.

The use of Kolofort in children under 18 years of age is contraindicated.

• For adult patients with IBS, it is recommended to prescribe Iberogast to reduce abdominal pain and normalize stool frequency and consistency [87–89].

GOR CLEL 5Grade of Recommendation – C (Level of Evidence – 5)

Comments: Iberogast is a combination herbal remedy obtained by alcoholic extraction from nine medicinal plants (Iberis amara, Angelica archangelica, Matricaria chamomilla, Carum carvi, Silybum marianum, Melissa officinalis, Mentha piperita, Chelidonium majus, Glycyrrhiza glabra). Iberogast is one of the most thoroughly studied herbal medicinal products [87, 88]. Experimental and clinical studies have established a multi-target action of Iberogast, which consists of normalizing motility in various parts of the gastrointestinal tract, reducing visceral sensitivity and increased gas production, as well as providing anti-inflammatory and antioxidant effects [89]. According to the results of placebo-controlled randomized trials, Iberogast effectively reduces the severity of disease symptoms (abdominal pain, diarrhea, constipation) in patients with IBS. According to data from studies involving over 46,000 patients, the incidence of adverse events did not exceed 0.04% [87].

In cases of a suspected diagnosis of functional dyspepsia and irritable bowel syndrome, as well as their combination, Iberogast may be prescribed immediately, prior to obtaining the results of a full workup, to reduce symptom severity [66].

The use of Iberogast in children under 18 years of age is contraindicated.

• For adult patients with IBS, it is recommended to consider prescribing #rebamipide, which normalizes mucosal-epithelial barrier permeability, at a dose of 100 mg 3 times daily for 8 weeks [90, 91].

GR CLE 2Grade of recommendation – C (Level of evidence – 2)

Comments: studies have yielded data on increased permeability of the gastrointestinal mucosal-epithelial barrier and the significant role of these changes in the development of symptoms in IBS patients, which provides a rationale for prescribing agents that normalize it. According to individual studies, the inclusion of #rebamipide in the treatment regimen achieves more effective relief of IBS symptoms and reduces the rate of relapse [90–92].

The use of rebamipide in children under 18 years of age is contraindicated.

3.4 Other treatment

Patients with IBS are recommended an initial psychiatric evaluation (examination, consultation) if ongoing treatment is ineffective, as well as in the presence of mood disorders, anxiety, or impulse control disturbances that significantly impact daily life, provided the patient gives consent [94].

CGR CLOE 2Clinical Practice Guideline Recommendation Grade – C (Level of Evidence – 2)

Comments: An evaluation of psychotherapeutic modalities showed success with cognitive behavioral therapy (NNT = 3), hypnotherapy (NNT = 4), multicomponent psychotherapy (NNT = 4), telephone-delivered therapy (NNT = 5), and dynamic psychotherapy (NNT = 3.5).

No significant improvement in patient well-being was achieved with relaxation therapy, cognitive-behavioral psychotherapy, online behavioral psychotherapy, stress management psychotherapy, or meditative psychotherapeutic practices.

Overall, however, the evidence base regarding the efficacy and adverse effects associated with behavioral techniques remains insufficient [39, 93].

In the pediatric population, data on the feasibility of yoga are inconclusive. On the one hand, short-term intervention was shown to be a feasible and safe complementary treatment for adolescents with IBS; on the other hand, no difference in treatment success was found when comparing yoga to no intervention [129, 130]. Benson's relaxation response may be a non-pharmacological solution to reduce symptom severity and improve the quality of life in children with IBS [131].

As in adults, various psychological interventions, such as cognitive behavioral therapy and hypnotherapy, have demonstrated efficacy in children with IBS, which may persist for many years after therapy cessation [132, 133].

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Specific rehabilitation measures for patients with IBS do not exist. According to available publications, cognitive behavioral therapy, hypnotherapy, and psychological support are effective in IBS [81, 95].

5. Prevention and Dispensary Observation

Specific preventive measures for IBS do not exist. Being a benign condition that does not increase the risk of organic gastrointestinal diseases, IBS does not require routine follow-up dispensary observation or control examinations. The decision to re-examine is made individually upon the appearance of new symptoms, primarily alarm symptoms, as well as in cases of treatment-refractory disease.

Vaccination

IBS is not a contraindication to vaccination with any type of vaccine (Order of the Russian Ministry of Health No. 1122n dated December 6, 2021, "On Approval of the National Schedule of Preventive Vaccinations and the Schedule of Preventive Vaccinations by Epidemiological Indications", Methodological Guidelines MU 3.3.1.1095-02. Medical Contraindications to Preventive Vaccinations with National Immunization Schedule Preparations), nor to vaccination against the novel coronavirus infection (COVID-19), in accordance with the product instructions.

6. Organization of Medical Care

Medical care, with the exception of medical care provided as part of clinical trials, in accordance with Federal Law No. 323-FZ of November 21, 2011 (as amended on May 25, 2019) "On the Fundamentals of Protecting the Health of Citizens in the Russian Federation", is organized and delivered:

1) in accordance with the regulations on the organization of medical care by types of medical care, approved by the authorized federal executive body;

2) in accordance with the regulations for the provision of care in the profiles "gastroenterology" and "coloproctology", which are mandatory for implementation across the Russian Federation by all medical organizations;

3) based on these clinical guidelines;

4) taking into account the standards of medical care approved by the authorized federal executive body.

Primary specialized health care is provided by a gastroenterologist, coloproctologist, and other medical specialists in medical organizations licensed to provide the corresponding types of medical activity. When IBS is suspected or detected in a patient, general practitioners, district general practitioners, family physicians, medical specialists, and mid-level medical personnel shall refer the patient in the established manner for a consultation to a medical organization that includes a gastroenterologist's office, coloproctologist's office, outpatient gastroenterological center (department), or outpatient coloproctological center (department) to receive primary specialized health care. Consultation in the said structural units of a medical organization must be conducted no later than 30 working days from the date of issuing the consultation referral. The gastroenterologist or coloproctologist of the medical organization that includes a gastroenterologist's office, coloproctologist's office, outpatient gastroenterological center (department), or outpatient coloproctological center (department) shall organize diagnostic examinations necessary to establish a diagnosis. If it is impossible to perform the diagnostic examinations necessary to establish a diagnosis, as well as in the presence of indications for inpatient medical care, the attending physician refers the patient to a gastroenterology department, coloproctology department, or another medical organization providing inpatient medical care to patients in the profile "gastroenterology", "coloproctology". The gastroenterologist or coloproctologist of a medical organization that includes a gastroenterologist's office, coloproctologist's office, outpatient gastroenterological center (department), or outpatient coloproctological center (department) refers the patient to medical organizations that have a gastroenterology department and/or coloproctology department for inpatient medical care in order to clarify the diagnosis (if the diagnosis cannot be established during the provision of primary specialized health care) and provide specialized medical care. The timeframe for initiating specialized medical care is determined by the decision of the patient selection commission for hospitalization. The timeframe must not exceed 30 calendar days from the date of issuing the hospitalization referral.

Specialized medical care for IBS is provided by gastroenterologists and coloproctologists in medical organizations that include a gastroenterology and/or coloproctology department, hold a license, possess the necessary material and technical base, and employ certified specialists in inpatient and day-hospital settings; it includes the prevention, diagnosis, and treatment of IBS, as well as medical rehabilitation.

Indications for hospitalization in a 24-hour or day hospital of a medical organization providing specialized medical care for IBS are determined by a medical panel of gastroenterologists and/or coloproctologists, involving other medical specialists if necessary. Indications for planned hospitalization in a medical organization are:

1) the need to perform complex interventional diagnostic medical procedures requiring subsequent monitoring in an inpatient or day-hospital setting;

2) presence of indications for specialized IBS treatment requiring monitoring in a 24-hour or day hospital setting.

Indications for discharging a patient from a medical organization are:

1) completion of a course of treatment or one of the stages of specialized medical care provision in a 24-hour or day hospital setting, provided there are no treatment complications requiring drug therapy and/or inpatient medical interventions;

2) refusal of the patient or their legal representative from specialized medical care in a 24-hour or day hospital setting determined by the medical panel of the organization providing IBS treatment, provided there are no complications of the underlying disease and/or treatment requiring drug therapy and/or inpatient medical interventions;

3) the need to transfer the patient to another medical organization according to the relevant medical profile.

The conclusion regarding the feasibility of transferring a patient to a specialized medical organization is made after a preliminary consultation based on submitted medical documents and/or a preliminary examination of the patient by medical specialists of the target organization.

Medical care for children with IBS can be provided on an outpatient basis, in a day hospital, or in an inpatient setting.

Types of medical care: planned, urgent, emergency.

Children with newly diagnosed IBS presenting with prominent clinical symptoms must undergo examination and treatment in gastroenterology or pediatric departments; in other cases, on an outpatient basis.

Comments: The duration of hospital stay is determined individually. Inpatient treatment of IBS patients outside of clinical exacerbations is generally inappropriate.

Children with mild to moderate IBS manifestations are subject to conservative treatment in an outpatient setting.

Children without clinical symptoms of IBS are monitored on an outpatient basis.

Children with IBS are followed up by a gastroenterologist or pediatrician (general practitioner/family physician); if necessary, consultation/treatment by a pediatric surgeon is performed.

Indications for inpatient treatment:

1) IBS with prominent clinical manifestations of exacerbation (pronounced abdominal pain syndrome, dyspeptic complaints, diarrheal syndrome, prolonged constipation);

2) Combination of IBS with somatic pathology, including gastrointestinal disorders;

3) Need for differential diagnosis with organic gastrointestinal pathology.

7. Additional Information

Available data on the prognosis of IBS course are ambiguous. According to the largest study, symptoms persist in the majority of IBS patients despite ongoing treatment, but do not worsen [96]. The probability of IBS symptom resolution during 12–20 months of follow-up is 38%. Factors negatively affecting the prognosis of the disease include reluctance to receive treatment, anxiety regarding disease-related risks, impaired daily functioning due to IBS, a long history of IBS, chronic stress, and concomitant psychiatric disorders.

Scientific data on the efficacy and safety of the following probiotic strains and formulations in IBS patients are presented (Table 2).

Table 2.

Probiotic strains and formulations effective in adults with IBS

FOS – fructooligosaccharides; IBS-C – irritable bowel syndrome with predominant constipation; IBS-D – irritable bowel syndrome with predominant diarrhea; Russian Ministry of Health CG – IBS diagnosis established in accordance with the Clinical Guidelines of the Russian Ministry of Health; ROME – IBS diagnosis established in accordance with the Rome criteria for the diagnosis of functional gastrointestinal disorders

Criteria for Evaluating the Quality of Medical Care

Criteria for assessing the quality of medical care in adults with IBS

Criteria for assessing the quality of medical care in children with IBS

Scope of application of the guidelines

These clinical guidelines are applicable when providing medical care within the framework of the Procedure for Providing Medical Care to the Adult Population with Gastroenterological Diseases, as well as within the framework of the Procedure for Providing Medical Care to Individuals with Diseases of the Colon, Anal Canal, and Perineum in Coloproctology.

References

Appendix A1. Working Group Composition

Composition of the Working Group

None of the working group members have any conflicts of interest

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. General practitioners

2. General practitioners (family physicians)

3. Gastroenterologists

4. Coloproctologists

5. Healthcare administrators

6. Expert physicians of medical insurance organizations (including when conducting medical and economic expertise).

Clinical guidelines reflect expert opinion on key issues. Clinical situations may arise that fall outside the scope of these recommendations; therefore, the final decision on the management tactics for each patient must be made by the attending physician, who bears the responsibility for their treatment.

Table A1. Levels of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Table P2. Scale for assessing the levels of reliability of evidence (LRE) for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitation interventions)

Table П3. Levels of Evidence for Recommendations (LER) grading scale for prevention, treatment and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Procedure for updating clinical guidelines

The clinical guideline update mechanism provides for systematic revision at least once every three years, as well as upon the emergence of new evidence-based data regarding the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or when justified additions/comments to previously approved clinical guidelines arise, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

These clinical guidelines were developed taking into account the Procedure for the Provision of Medical Care to the Population in the Profile "Gastroenterology" (approved by Order of the Ministry of Health of the Russian Federation No. 906n dated November 12, 2012).

Order of the Ministry of Health of the Russian Federation No. 330 dated August 5, 2003, "On measures to improve clinical nutrition in healthcare institutions of the Russian Federation".

Order of the Ministry of Health of the Russian Federation No. 395n dated June 21, 2013, "On the approval of clinical nutrition norms".

Order of the Ministry of Health of the Russian Federation No. 1008n dated September 23, 2020, "On approval of the procedure for providing patients with clinical nutrition".

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

Irritable bowel syndrome (IBS) is a very common functional bowel disorder. The term "functional" indicates that your symptoms are related to changes in bowel function rather than anatomical changes, inflammation, tumor cells, etc. The diagnosis of this disease is definitively established after excluding the most probable organic diseases. Having IBS does not increase your probability of getting cancer, Crohn's disease, and other serious conditions. Treatment for IBS is almost always long-term and requires a combination of several medications, as they do not always have a sufficient effect individually. In addition to medications (spasmolytics, probiotics, dietary fiber supplements), psychotherapeutic interventions and even general measures such as yoga, meditation, and regular physical exercise are extremely effective. Patients with IBS often experience several types of symptoms simultaneously (not only abdominal pain, but also constipation, diarrhea, abdominal bloating, joint pain, general malaise). However, when communicating with your doctor, try to highlight the main manifestation of IBS that most significantly affects your ability to work, well-being, and social interaction. Drug treatment and psychotherapy should be focused precisely on this main manifestation of IBS.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Russian title: Bristol Stool Form Scale

Original title: Bristol Stool Form Scale

Source: Brian E. Lacy, Fermín Mearin, Lin Chang, William D. Chey, Anthony J. Lembo, Magnus Simren, Robin Spiller. Bowel disorders. Gastroenterology 2016;150:1393–1407.

Type:

- rating scale

- index

- questionnaire

- other (specify):

Purpose: identification of the nature of stool disorders

Content (template):

Key (interpretation): the Bristol Stool Form Scale is used to describe stool consistency, according to which firm stool corresponds to types 1 and 2, while liquid stool corresponds to types 6 and 7

Notes: −.