Lack of lasting effectiveness of PEG 3350 laxative treatment of constipation.

Purpose: PEG 3350 (MiraLax, Braintree Laboratories Inc., Braintree, MA) 17 g daily has been shown to be safe and effective in a 14-day trial for constipation. This present investigation was designed to extend the treatment and safety experience with PEG 3350 and to evaluate any lasting effectiveness during a 30-day post-treatment observation period.

Methods: Study subjects met Rome II criteria for constipation and reported <3 bowel movements a week. They were treated with PEG 3350 17 g daily for 14 days. Treatment efficacy was defined by resolution of constipation symptoms as determined by the Rome II and stool frequency definitions during the treatment period.

Results: Fifty healthy constipated subjects formed the study group. There were 42 females and 8 males. Mean age was 52 +/- 15.5 years (+/-SD). Symptom duration was 22.6 +/- 16.7 months (+/-SD). At baseline, all had <3 bowel movements a week and met Rome II criteria. Two were lost to follow-up. Two took enemas or laxatives and 2 discontinued active treatment because of "gas" and were considered treatment failures. At the end of 14 days, 40 of 48 (83.3%) had >3 stools in the last week and no longer met Rome criteria. Thirty-two of 45 (71.1%) reported satisfaction with the first bowel movement after initiating treatment. Thirty days after active treatment, 29 of 47 (61.7%) responded that they needed laxative treatment.

Conclusion: PEG 3350 relieved constipation in most treated study subjects. During a 30-day post-treatment observation period, 29 of 47 (61.7%) had additional constipation treatment interventions.