Constipation in Children

🔍 When to Suspect

Infrequent bowel movements (<3/week), passage of hard, large stools, straining, or paradoxical overflow soiling (encopresis)

From the full topic in The Ocean Library: Constipation in Children

🧭 When to suspect

Constipation is one of the commonest reasons a child is brought to primary care, affecting up to 30% of children at some point. The great majority is idiopathic (functional) – there is no anatomical, neurological or metabolic cause – and the diagnosis is made clinically from the history and examination, not from a test. Suspect it when a child passes stools fewer than three times a week, strains, passes hard, large or pellet-like (‘rabbit dropping’) stools, or has pain on defecation.

The mechanism that matters is the vicious cycle: a single painful or frightening motion leads the child to withhold, the retained stool grows larger and harder, the next motion hurts more, and withholding deepens. Over time the rectum stretches and loses sensation, and soft stool leaks around the hard impacted mass – overflow soiling (encopresis). This loose leakage is frequently mistaken for diarrhoea, when it is in fact a sign of severe constipation.

Two or more of the features below indicate constipation (use the Bristol Stool Form Scale to grade consistency). The key clinical skills are to recognise faecal impaction (which must be cleared before maintenance), and to exclude red flags that point away from idiopathic constipation.

In a child younger than 1 year	In a child/young person older than 1 year
• Fewer than 3 complete stools per week (type 3–4)*	• Fewer than 3 complete stools per week (type 3–4)
• Hard, large stool; ‘rabbit droppings’ (type 1)	• ‘Rabbit droppings’ (type 1); large stools that block the toilet
• Distress, straining or bleeding with a hard stool	• Overflow soiling – loose, very smelly stool passed without sensation
• Onset after the first few weeks of life, often with a precipitant (fissure, change of feed)	• Retentive posturing (straight-legged, tiptoe, back-arching); appetite that improves after a large stool

* Does not apply to an exclusively breastfed baby after 6 weeks of age, who may normally go several days between soft stools.

Source: NICE CG99 · NICE QS62

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