Constipation in Children

Definition

Constipation in children is defined as infrequent, hard, or painful bowel movements, often associated with stool retention, abdominal discomfort, or fecal incontinence. It can be functional or secondary to underlying medical conditions.

Epidemiology

• Affects approximately 3–30% of children worldwide
• Peak incidence between 2–4 years of age
• Functional constipation accounts for over 90% of cases
• Higher prevalence in children with low fiber intake or inadequate fluid consumption
• More common in boys in early childhood, but prevalence equalizes later

Etiology

• Functional constipation: voluntary stool withholding due to pain or behavioral issues
• Dietary factors: low fiber, insufficient fluids
• Secondary causes: hypothyroidism, celiac disease, Hirschsprung disease, spinal cord anomalies, medications (opioids, anticholinergics)
• Psychosocial factors: stress, toilet training difficulties, school avoidance
• Family history of constipation increases risk

Pathophysiology

• Delayed colonic transit or outlet obstruction leads to stool accumulation
• Retention causes colon distension and impaired motility
• Hard stool formation increases pain, promoting further withholding
• Rectal distension reduces sensation of defecation, exacerbating chronic constipation
• Chronic constipation can lead to fecal impaction, overflow incontinence, and secondary behavioral changes
• Altered gut microbiota may contribute to functional constipation