Double-blind randomized evaluation of clinical and biological tolerance of polyethylene glycol 4000 versus lactulose in constipated children

J Pediatr Gastroenterol Nutr. 2005 Nov;41(5):625-33. doi: 10.1097/01.mpg.0000181188.01887.78.


Objectives: To assess the safety of a polyethylene glycol (PEG) 4000 laxative without additional salts in pediatric patients.

Study design: This was a 3-month multicenter, randomized, double-blind, double-dummy, lactulose-controlled, parallel study enrolling 96 ambulatory constipated children aged 6 months to 3 years, treated daily with 4-8 g PEG or 3.33 g-6.66 g lactulose. Total protein, albumin, iron, electrolytes, and vitamins B9 (folates), A and D (25OHD3) were measured in blood before and after treatment (day 84) in a central laboratory.

Results: The percentage of children with at least one value out of normal range at day 84 with respect to baseline status (with or without at least one value out of normal range), i.e. the primary endpoint, was 87% and 90% in the PEG and lactulose groups, respectively, without any difference between groups. The whole blood parameters showed no qualitative or quantitative treatment-related changes. Vitamin A values were above normal range in 56% and 41% of children at baseline versus 33% and 36% at day 84 in the PEG and lactulose groups, respectively. Iron values were similarly under normal range in 47% and 51% at baseline versus 42% and 51% at day 84. Clinical tolerance was similar for both treatments except for vomiting and flatulence, which were significantly higher with lactulose. Significantly higher improvements were evidenced with PEG regarding stool consistency, appetite, fecaloma and use of additional laxatives.

Conclusion: This 3-month study in 96 constipated children aged 6 months to 3 years confirms the long-term tolerance of PEG 4000 in pediatrics and indicates a PEG efficacy similar to or greater than that of lactulose.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cathartics* / adverse effects
  • Cathartics* / therapeutic use
  • Child, Preschool
  • Constipation / blood
  • Constipation / drug therapy*
  • Consumer Product Safety*
  • Defecation / drug effects
  • Digestion / drug effects
  • Double-Blind Method
  • Electrolytes / blood
  • Female
  • Flatulence / chemically induced
  • Gastrointestinal Agents / adverse effects
  • Gastrointestinal Agents / therapeutic use
  • Humans
  • Infant
  • Intestinal Absorption / drug effects
  • Lactulose* / adverse effects
  • Lactulose* / therapeutic use
  • Male
  • Polyethylene Glycols* / adverse effects
  • Polyethylene Glycols* / therapeutic use
  • Safety
  • Treatment Outcome
  • Vitamins / blood
  • Vomiting / chemically induced


  • Cathartics
  • Electrolytes
  • Gastrointestinal Agents
  • Vitamins
  • Polyethylene Glycols
  • Lactulose