Prune intake ameliorates chronic constipation symptoms and causes little discomfort from diarrhea and loose stools: A randomized placebo-controlled trial

Aim Little data is available regarding the effectiveness of natural foods in treating chronic constipation. We aimed to identify whether prune ameliorates chronic constipation and can be used safely for a relatively long time. Methods In this double-blind, randomized, placebo-controlled trial, 84 subjects with chronic constipation, presenting more than 6 months before and persisting for more than 3 months, were randomized to prune (n=42) or placebo (n=42) intake for 8 weeks. We assessed daily Bristol stool form scale (BSFS) scores and stool frequencies and administered the gastrointestinal symptom rating scale (GSRS) questionnaire, as primary outcomes for constipation improvement. Results The prune group showed significantly decreased rates of hard stool (BSFS1 or 2) and increased rates of normal stool (BSFS 3 or 4) after 1 week, which were more evident after 7 weeks between the two groups. Prune significantly increased stool frequency immediately after 1 week. Furthermore, GSRS of hard stools, flatulence, and incomplete evacuation significantly improved after 4-8 weeks of prune intake, of which constipation and hard stools were significantly reduced compared to the placebo group. In contrast, prune intake did not cause diarrhea, loose stools, or urgent need for defecation during 8 weeks evaluated by GSRS score. We found no abnormal laboratory tests of liver function, renal function, inflammation, or urinalysis after prune intake. Conclusions Daily prune intake ameliorates chronic constipation, improving quality of life, and causes few diarrhea-related symptoms or side effects. Our results emphasize a new, useful, and easy strategy for chronic constipation. (UMIN ID:000041384)