A dietary fiber mixture versus lactulose in the treatment of childhood constipation: a double-blind randomized controlled trial.

Background: Constipation is a common problem in children. As first-line treatment, increased dietary fiber is often advocated. To our knowledge, however, no large studies evaluating the effect of dietary fibers in childhood constipation have been published.

Patients And Methods: A randomized, double-blind, prospective controlled study was performed. Patients received either a fiber mixture or lactulose in a yogurt drink. After a baseline period of 1 week, patients were treated for 8 weeks followed by 4 weeks of weaning. Polyethylene glycol 3350 was added if no clinical improvement was observed after 3 weeks. Using a standardized bowel diary, parents recorded defecation frequency during the treatment period. In addition, incontinence frequency, stool consistency, presence of abdominal pain and flatulence, necessity for step-up medication, and dry weight of feces were recorded, as were adverse effects.

Results: A total of 147 children were eligible; 12 children wished not to participate. Of the remaining children, 65 were randomized to treatment with fiber mixture and 70 to treatment with lactulose. In all, 97 children completed the study. No difference was found between the groups after the treatment period concerning defecation frequency (P = 0.481) and fecal incontinence frequency (P = 0.084). However, consistency of stools was softer in the lactulose group (P = 0.01). Abdominal pain and flatulence scores were comparable (P = 0.395 and P = 0.739, respectively). The necessity of step-up medication during the treatment period was comparable (P = 0.996), as were taste scores (P = 0.657). No serious adverse effects were registered.

Conclusions: A fluid fiber mixture and lactulose give comparable results in the treatment of childhood constipation.