Paediatric Constipation Medicines

Functional constipation is common in children and is treated in three steps: clear any faecal impaction, give daily maintenance laxative, and continue for months after normal stools return. Withholding behaviour, painful stools and toilet-related fear drive the cycle, so early and sufficient laxative dosing prevents chronic constipation.

Red flags. Delayed passage of meconium beyond 48 hours, constipation from the first weeks of life, ribbon stools, abdominal distension, vomiting, failure to thrive, leg weakness, sacral dimple or tuft, and an empty rectum with a palpable mass. These need exclusion of Hirschsprung disease, hypothyroidism and spinal cord lesions.

• Disimpaction: macrogol 3350 (polyethylene glycol) 1 to 1.5 g/kg/day orally, maximum 100 g/day, for 3 to 6 days, taken with enough fluid. Add a stimulant laxative if there is no response in 2 weeks. Rectal treatments are used only if oral treatment fails.
• Maintenance: macrogol 3350 0.4 to 0.8 g/kg/day, adjusted to give a soft stool daily. Continue for at least 2 months after stools are normal and then taper over months.
• Where macrogol is not available: lactulose 1 to 3 mL/kg/day (of 3.35 g/5 mL) in two divided doses, maximum 60 mL/day, though it is more likely to cause bloating.
• Stimulant add-on: senna 2.5 to 5 mg at night (2 to 6 years) or 5 to 10 mg at night (6 to 12 years); bisacodyl 5 mg orally at night (4 to 10 years), 5 to 10 mg (over 10 years).
• Rectal: glycerol suppository 1 g (under 1 year), 2 g (1 to 12 years); bisacodyl suppository 5 mg (2 to 10 years). Phosphate enemas are avoided under 3 years and in Hirschsprung disease, because of hyperphosphataemia.
• Infants: for infants under 1 year, dietary measures and a short course of glycerol suppository or lactulose are used first.

Titration. Increase the maintenance dose by 25 to 50% every few days if stools stay hard, and reduce if stools become watery. Avoid stopping suddenly.

Behavioural support. Scheduled toilet sitting after meals for 5 minutes, a reward chart, adequate fluid and fibre, and no punishment.

Opioid-induced constipation. Start a laxative with the first opioid dose; macrogol or senna is used.

Kidney and liver impairment. Avoid phosphate enemas and magnesium-containing laxatives in kidney impairment.

Special groups. Adolescents need privacy for toilet use and review of drugs that cause constipation (opioids, anticholinergics, iron). In East Africa, lactulose, senna and glycerol suppositories are the usual options when macrogol is not stocked.

Monitoring. Review stool frequency, form and pain at 2 weeks, then every 1 to 2 months. Track soiling, growth and abdominal examination.

Referral and escalation. Refer for failed disimpaction after 2 courses, red flags, constipation with failure to thrive, or suspected Hirschsprung disease.

Stopping. Continue maintenance until the child has had regular soft stools without withholding for at least 2 months, then reduce gradually over weeks to months. Restart if symptoms return.