Background Chronic functional constipation is one of the most referred conditions in Paediatric Gastroenterology practice. Osmotic and/or stimulant laxatives are used to treat and prevent future impaction and promote regular bowel habits. From available evidence, polyethylene glycol (PEG) is effective for both disimpaction and maintenance therapy in children with chronic constipation. Its paediatric preparation is currently licensed for use in children above 2 years of age in the United Kingdom.

Objective We reviewed the literature to evaluate the efficacy and safety of PEG in children below 2 years.

Methods We searched the Cochrane Library, Pubmed and Medline (1950 to 2007), Cinahl (1982–2007) and Embase (1974–2007) using search words ‘Constipation OR fecal impaction OR disimpaction’, AND ‘polyethylene glycol OR macrogol OR movicol’ in infants and children below 2 years. Five relevant studies were found. Meta-analysis was carried out to identify safety issues and efficacy of PEG in constipation.

Results Safety: No serious adverse events were reported. The most common side effect was diarrhoea which resolved on dose reduction. Rarely, children reported increased flatulence and decreased palatability. Efficacy: PEG (3350 or 4000) was an effective treatment for constipation even in children below 2 years of age. In trials against lactulose, PEG was equally well tolerated. One trial suggested PEG was marginally more effective by virtue of fewer adverse effects.

Conclusion PEG is an effective treatment for functional constipation in children below 2 years. The common side effect, diarrhoea resolved on dose reduction.