New polyethylene glycol laxative for treatment of constipation in adults: a randomized, double-blind, placebo-controlled study

South Med J. 2001 May;94(5):478-81.


Background: This study evaluated the safety and effectiveness of a new polyethylene glycol (PEG) laxative (MiraLax, Braintree Laboratories Inc, Braintree, Mass) in 23 patients reporting a history of constipation.

Methods: After a 7-day placebo control period, patients were randomized into a double crossover trial of placebo versus 17 g of PEG daily for 4 days. Patient maintained a stool diary.

Results: Daily ingestion of a 17 g dose of PEG increased mean daily bowel movement frequency to once per day by the last 7 days of the 14-day treatment period. This was a statistically significant improvement over placebo, which provided about 1 bowel movement every 2 days during the last week of therapy. Patient diary ratings of related subjective symptoms were improved with PEG treatment over placebo. Both investigator and patients rated PEG therapy superior to placebo. No clinically significant changes in blood chemistry, complete blood count (CBC), or urinalysis were observed.

Conclusions: Daily therapy with 17 g of PEG laxative for 14 days resulted in a significant improvement in bowel movement frequency in constipated patients relative to placebo by the second week of treatment.

Publication types

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

MeSH terms

  • Adult
  • Cathartics / therapeutic use*
  • Constipation / drug therapy*
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Polyethylene Glycols / therapeutic use*


  • Cathartics
  • Polyethylene Glycols