Childhood constipation is typically characterised by infrequent bowel evacuations, large stools, and difficult or painful defecation.
Symptoms usually result from low-fibre, poor-nutrient intake and too little water, which leads to high levels of colonic reabsorption of water and hardening of the stool. This starts as an acute problem but can progress to faecal impaction and chronic constipation.
Any cause of painful defecation may provoke active withholding.
Duration of delayed defecation and degree of impaction may depend on capacity of the child's rectum or the degree of megarectum.
After faecal disimpaction, maintenance laxatives are essential and are often required for many months or years to reduce relapse risk.