Irritable bowel syndrome

Causes and mechanisms of development

The disease is based on impaired neuroendocrine regulation of the interaction between the brain and the gut. The main pathogenetic mechanism is the development of visceral hypersensitivity, which disrupts normal bowel motility.

Hypersensitivity can be triggered by:

• local inflammation;
• gastrointestinal trauma;
• food allergy;
• prior intestinal infections.

Risk factors for IBS include a positive family history (functional disorders in parents) and psychoemotional disturbances in the child (chronic stress, anxiety, depression).

Diagnostic criteria

IBS is diagnosed when symptoms last for at least 2 months and organic diseases are fully ruled out.

Key diagnostic features:

1. Abdominal pain bothers the child at least 4 days per month.
2. The pain syndrome is strictly associated with defecation, changes in stool consistency, or frequency.
3. In IBS with constipation, pain does not resolve even after stool normalization.

Classification

The IBS subtype is determined by which bowel habit disturbance is dominant. There are four clinical variants:

• IBS with predominant diarrhea;
• IBS with predominant constipation;
• IBS with mixed symptoms (alternating constipation and diarrhea);
• Unclassified (nonspecific) IBS.

Differential diagnosis

The main rule when suspecting IBS is to exclude organic pathology, especially if "red flags" (red flags) are present. Non-invasive markers are used for this: fecal calprotectin (to rule out intestinal mucosal inflammation) and C-reactive protein (to rule out systemic inflammation).

Conditions for differential diagnosis depend on the IBS subtype:

• In diarrhea-predominant IBS, infections, inflammatory bowel disease (IBD), celiac disease, and lactase deficiency should be ruled out.
• In constipation-predominant IBS, screening is needed for metabolic disorders, organic developmental anomalies of the colon, and spinal cord pathologies disrupting pelvic innervation.

Principles of treatment

IBS therapy is always multimodal, with priority given to non-pharmacological approaches.

1. Psychological correction and lifestyle adjustments: Explaining the benign nature of the disease to parents and the child, establishing proper bowel habits (keeping a diary, positive reinforcement, regular scheduled toilet sits), and psychological support if needed.

2. Medical nutrition therapy:

• For constipation: increased fluid intake, dietary fiber, and foods that stimulate peristalsis (fermented dairy products, vegetables, fruits).
• 3. Pharmacotherapy: Basic support includes herbal sedatives with a mild antispasmodic effect, pro- and prebiotics, and enzymes. Symptomatic treatments include antispasmodics for pain relief, antiflatulents, as well as laxatives (for constipation) or antidiarrheal drugs (for diarrhea).

For diarrhea: binding foods, restriction of fermentable carbohydrates.

Class and exam questions

What else to study on this topic

• Mechanisms of visceral hypersensitivity development
• Spectrum of somatic complaints accompanying IBS in children
• Features of the elimination diet in diarrhea-predominant IBS
• Pharmacological groups of antispasmodics used in pediatrics

Other topics in "Chapter 7. Digestive System Diseases"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.