A nice review (Holtmann G, Talley NJ. Clin Gastroenterol Hepatol 2015; 13: 422-32) provides a summary of the experience of herbal medicines for disorders that include irritable bowel syndrome (IBS), functional dyspepsia, and inflammatory bowel disease (IBD).
A recurring theme in the review is that herbal medicines are poorly studied and vary greatly in the quality of their manufacturing. “Physicians and regulators need to remain very cautious about the use of herbal remedies.” The available trials, with a long list of plant extracts, are summarized in tables in the review.
- “A meta-analysis also showed that supplementation of peppermint oil, in addition to pharmacologic standard treatments, was of benefit to both constipation-predominant IBS and diarrhea-predominant IBS patients.”
- “The use os STW5 [iberogast] also has been found to be effective compared with placebo in the treatment of IBS symptoms.”
- Very small clinical studies have suggested possible efficacy of aloe vera and curcumin in the treatment of IBD.
- Adverse effects: “there are numerous case reports on adverse events related to herbal medicines.” Some of these have been severe.
- “The main driver for the use of herbal and complementary medicines is the unmet need of patients.” However, given that these preparations are non patentable, “there is limited investment of producers.”
Bottomline: There is little financial incentive for companies to determine more conclusively whether these agents are effective for functional disorders or for inflammatory bowel disease.
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