Functional constipation

Definition and causes

Overall, constipation is divided into two main groups:

• Primary: strictly functional (idiopathic) disorders. These account for the vast majority of cases (up to 95% of patients).
• Secondary: occur as a symptom secondary to another underlying issue, such as organic lesions of the gastrointestinal tract, endocrine, or neurological disorders.

Organic forms often manifest from birth and are characterized by a gradual deterioration in the child's condition, indicating decompensation of bowel function. Functional variants, on the other hand, are closely associated with age-related changes and the individual developmental rate of the large intestine.

Diagnostic criteria

To establish a diagnosis in children, the Rome IV criteria are used. It is required that at least once a week for 1 month the child exhibits at least 2 of the following signs:

1. Defecation 2 or fewer times per week (in children older than 4 years).
2. At least one episode of fecal incontinence per week.
3. Specific behavior: the child adopts unusual postures in an attempt to retain stool.
4. Pain during peristalsis and defecation.
5. Physical examination reveals a large accumulation of stool in the rectum.
6. Periodic passage of excessively large-diameter stool (parents often note that such stool clogs the toilet).

Crucial condition: the diagnosis is made only after organic pathology has been excluded.

Diagnostics and Red Flags

In typical functional constipation, instrumental examination is usually not necessary—treatment is initiated immediately. However, the physician always evaluates the presence of "alarm symptoms" (red flags) indicating potential congenital malformations, neurological, or metabolic disorders.

Warning signs include:

• Onsets of constipation immediately after birth.
• Failure to pass meconium within the first 48 hours.
• Physical or motor development delay.
• Severe meteorism and vomiting.

If red flags are present, an in-depth examination is prescribed. Depending on the suspected conditions, this may include colonoscopy (for Hirschsprung's disease or IBD), esophagogastroduodenoscopy (for celiac disease), spinal MRI (for myelodysplasia), a fecal pancreatic elastase test (for cystic fibrosis), or thyroid hormone level assessment.

Treatment and Prevention

Therapy is selected individually and is always comprehensive. The baseline level is non-pharmacological correction: a high-fiber diet (vegetables, fruits, bran) for children over 1 year of age, adequate fluid intake, and the addition of probiotics and prebiotics. Physical activity (exercise therapy) is also important to strengthen the pelvic floor muscles and stimulate motility.

However, diet alone is not enough at the start; medication is required.

Laxative groups:

• Bulk-forming: dietary fiber (psyllium seed husk).
• Osmotic: macrogol (first-line drug for chronic constipation) and lactulose (an alternative).
• Motility-stimulating: sodium picosulfate (prescribed for short courses only).
• Softening: liquid paraffin.
• Topical: rectal formulations (often used for acute constipation).

Class and exam questions

What else to study on this topic

• Mechanism of action of osmotic laxatives
• Hirschsprung's disease as a cause of organic constipation
• The role of biofeedback therapy in the treatment of constipation in children
• Specifics of performing a digital rectal examination in children

Other topics in "Chapter 7. Digestive System Diseases"

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