A randomized, double-blind, placebo-controlled trial of St John's wort for treating irritable bowel syndrome.
OBJECTIVE
St John's wort (SJW) is known to effectively treat patients with mild-to-moderate depression. Antidepressants are frequently used to treat irritable bowel syndrome (IBS). To date, no study that examines the efficacy of SJW in IBS has been carried out. The aim of this study was to evaluate the efficacy of SJW in IBS after 12 weeks.


METHODS
In this randomized, double-blind, placebo-controlled trial, 70 participants with an established diagnosis of IBS were randomized and assigned by concealed allocation to either SJW or placebo. Both treatment arms were balanced on symptom subtype. The primary end point was self-reported overall bowel symptom score (BSS) at 12 weeks. Secondary end points were individual BSS for diarrhea (D-BSS), constipation (C-BSS), pain or discomfort, and bloating; adequate relief (AR) of IBS on at least 50% of the last 4 weeks of therapy; and IBS quality-of-life score at 12 weeks.


RESULTS
In all, 86% of the participants were women, and the median age was 42 years. Overall, 29% had C-IBS, 37% D-IBS, and 31% had mixed IBS. Both groups reported decreases in overall BSS from baseline, with the placebo arm having significantly lower scores at 12 weeks (P=0.03) compared with SJW. These patterns of improvement were mirrored in the secondary end points with the placebo group faring better than the SJW-treated group, with significant differences observed at week 12 for D-BSS (P=0.03) and percent with AR (P=0.02). A similar proportion of subjects in each treatment group (SJW: 51% vs. placebo: 54%) believed that the study drug they received decreased IBS life interferences (P=0.79).


CONCLUSIONS
SJW was a less effective treatment for IBS than placebo.
Saito
Yuri A
YA
Mayo Clinic, Rochester, Minnesota 55905, USA. saito.yuri@mayo.edu
Rey
Enrique
E
Almazar-Elder
Ann E
AE
Harmsen
W Scott
WS
Zinsmeister
Alan R
AR
Locke
G Richard
GR
Talley
Nicholas J
NJ
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D020902:Hypericum; D043183:Irritable Bowel Syndrome / Q000188:drug therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy / Q000379:methods*; D010919:Placebos; D011788:Quality of Life; D016896:Treatment Outcome
D010919:Placebos