According to an article that was published in the October 2009 issue of the American Journal of Gastroenterology, St. John's wort is a less effective treatment for irritable bowel syndrome (IBS) than a placebo. A placebo is a preparation containing no active ingredients and is given to a patient participating in a clinical trial in order to assess the performance of a new drug given to other patients in the trial. (1)
Lead author, Yuri Saito, M.D., MPH, of the Mayo Clinic in Rochester, Minnesota, explained the hypothesis for St. John's wort treatment: "Several of the chemical neurotransmitters that are in the brain are also in the colon. Therefore, it's been thought that antidepressants may affect sensation in the colon in a similar way to how they affect sensation in the brain. Our goal was to evaluate the usefulness of St. John's wort {an herbal antidepressant] in treating IBS." (2)
In this trial, 70 IBS patients were randomly assigned to receive either St. John's wort or a placebo for a 12 week period. The median age of the participants was 42 years old and 86% were female and 14% were male. The breakdown of symptoms was 29% had constipation-predominant IBS, 37% had diarrhea-predominant IBS, and 31% had mixed IBS. The study outcome relied on self-reported overall bowel syndrome scores (BSS) and secondary scores allotted for occurrence of diarrhea and constipation, pain or discomfort, and bloating. Limitations of this study were the exclusion of patients with moderate to severe IBS or with the additional diagnosis of depression, small sample size with a disproportion of female subjects, and the inability to determine efficiency in subtypes of IBS.
Overall, BSS decreased from baseline in both groups. By week 12, subjects in the placebo group had lower BSS. Reduced interference with life activities was reported in 51% of the St. John's wort group and in 54% in the placebo group.
"Unfortunately, our study showed that St. John's wort was not successful in helping IBS patients. However, well-designed studies of herbal supplements are important so that physicians and patients can make informed decisions about which supplements to recommend or try," concludes Dr. Saito. (2)
(1) Encarta World English Dictionary 1998-2005 Microsoft Corporation
(2) www.medscape.com
Maryann Gromisch is a registered nurse with clinical experience in medical/surgical nursing and critical care. She has experience assisting a gastroenterologist in a private practice setting.