Polyethylene glycol (PEG) 3350 is an osmotic laxative used for the treatment of occasional constipation. Lily Tran, MD, and Jack DiPalma, MD, recently conducted a study confirming the short-term efficacy of PEG 3350 during a 14-day treatment period and evaluating its residual effectiveness during a 30-day posttreatment observation period. The participants (n = 50; 42 women; mean age, 52 years; mean symptom duration, 22.6 months), who met Rome II criteria for constipation and reported <3 bowel movements a week, were treated with PEG 3350 17 g/day for 14 days.
During treatment, 2 participants were lost to follow-up, 2 took enemas or other laxatives, and 2 discontinued because of flatulence. At the end of treatment, 83.3% (40/48) had >3 stools in the last week and no longer met Rome criteria. After the 30-day observation period, 61.7% (29/47) reported needing laxative treatment. These results, reported in the Journal of Clinical Gastroenterology (August 2005), revealed that, although PEG 3350 effectively relieved constipation during the treatment period, it did not offer lasting effectiveness in most participants once treatment was stopped.