Treatment of diarrhea-predominant irritable bowel syndrome with traditional Chinese herbal medicine: A randomized placebo-controlled trial

BACKGROUND: As there is no effective treatment for irritable bowel syndrome (IBS), many patients turn to traditional Chinese medicine (TCM) for possible cure. We investigated the therapeutic efficacy of an ancient herbal Chinese formula in patients with diarrhea-predominant IBS. METHODS: This was a randomized double-blinded placebo-controlled trial. Chinese IBS patients with predominant diarrhea symptoms that fulfilled Rome II criteria were recruited. The diagnosis was verified by a TCM herbalist using TCM criteria. Eligible patients were randomized to receive a standard preparation of TCM extracts that contained 11 herbs or placebo with similar appearance and taste for 8 wk after a 2-wk run-in period. Patients were followed up for an additional 8 wk post-treatment. Primary outcome was patient's global symptom assessment. Other outcome measures included individual IBS symptom scores and health-related quality of life (short form 36). RESULTS: One hundred nineteen patients were randomized: 60 to receive TCM and 59 to receive placebo. There was no significant difference in the proportion of patients with global symptom improvement between the TCM and placebo groups at week 8 (35% vs 44.1%, p = 0.38) and at week 16 (31.7% vs 33.9%, p = 0.62). Moreover, there was no difference in individual symptom scores and the quality-of-life assessment between the two groups at all time points. BACKGROUND: The use of this herbal formulation for diarrhea-predominant IBS did not lead to global symptom improvement. Further controlled clinical studies may be necessary to characterize the role of TCM in the management of IBS.