Constipation is a highly prevalent disorder affecting all ages. Women and the elderly are particularly prone to develop constipation. The adverse impact on quality of life is similar to that seen in patients with diabetes, dermatitis, chronic allergies. A multicenter, randomized, placebo-controlled trial was conducted to evaluate the effectiveness and safety of polyethylene glycol (PEG) 3350 in individuals who self-reported occasional bouts of constipation. The researchers enrolled 203 subjects, aged ≥ 17 years for the study; of these, 102 were randomly assigned to treatment with PEG 3350 17 g once daily for a week, while 101 patients received placebo. Ninety-eight participants (96.1%) in the PEG 3350 group and 94 (93.1%) in the placebo group completed the study. Eleven subjects failed to completely adhere to the study protocol and hence were excluded from the analysis. 

Thirty-six of the 98 (36.7%) study subjects in the PEG 3350 group reported complete resolution compared to 23 (24.5%) of the 94 in the placebo group. A complete bowel movement without any straining to pass stool and passage of hard/lumpy stools for a minimum of two days was regarded as complete resolution. No occurrence of ≥2 consecutive unsuccessful bowel movements after the first successful bowel movement was also considered as complete resolution.

The visual analog scale (VAS) score for hard stools in PEG 3350 group was 29.0 vs 45.3 in the placebo group. The score was 21.1 vs 37.8, respectively for the symptom of straining. Significant relief in straining and decrease in hard stools over the duration of the study was noted in subjects treated with PEG 3350. Complete bowel movements without straining or lumpy stools occurred more often in PEG treated patients compared to those who received placebo; 34% vs 18.4%, respectively. PEG 3350 also improved control over a bowel movement and provided better relief from associated symptoms like bloating and cramping. This improved the quality of daily life and patients preferred PEG over their usual laxative. No between-group differences were noted for adverse events. No serious adverse events or deaths occurred and no participant stopped treatment due to adverse effects. The study therefore concluded that PEG 3350 administered orally once a day for a week is safe and effective in patients who experience occasional constipation.

McGraw T, et al. World J Gastrointest Pharmacol Ther. 2016 May 6;7(2):274-82.