Herbal medicine for IBS [Feb 1999; 60-7]

Herbal medicine for IBS
Design Results Comment

As many as 20% of the population may suffer from irritable bowel syndrome (IBS) at some time or another. It is characterised by recurrent or chronic abdominal pain, with distension and disturbed defecation. Many people just live with it, but for some it has a large impact on their lives.

It is a condition for which many people seek alternative therapy, often without any clear evidence. For the use of Chinese herbal medicine, a new, high-quality randomised trial [1] provides good evidence for effectiveness.

Design

This trial randomised people with IBS to receive a placebo, or standard or individualised Chinese herbal medicine. The trialists went to a great deal of trouble to ensure the high standard of the study:

They ensured that the herbal medicines used both for standard treatment and for individualised treatment came from a common Chinese herbal pharmacopoeia.
They ensured that placebo was similar in taste and appearance to the Chinese medicine.
They made the waiting time for medicines standard.
They used a standard diagnosis for IBS.
They used standard scales for IBS symptoms and severity.
They used patient and gastroenterologist scoring independently.
They used blinded evaluators.

After two weeks run in, patients were randomised, and then saw their herbal practitioner at two-week intervals for two occasions, and then monthly for a further two occasions, with continuous treatment for 16 weeks in all. At the end of 16 weeks there was a rating of success (improved, same, worse) by patient and gastroenterologist.

Results

A bowel symptom scale (BSS) was used to assess change in IBS symptoms. It consisted of 100 mm visual analogue scales measuring pain/discomfort, bloating, constipation and diarrhoea. Over 16 weeks there was a significant reduction in BSS as judged by patients for standard and individualised Chinese herbal medicine treatments, but not for placebo (Figure).

At the end of 16 weeks 29/38 patients judged their IBS to have improved on standard treatment, 18/28 on individualised treatment, and 11/33 on placebo. This gives NNTs for IBS improvement after 16 weeks of treatment of 2.3 (95%CI 1.6 to 4.6) for standard treatment and 3.2 (1.8 to 14) for individualised treatment.

Adverse effects were minor, with two patients withdrawing from the treatment because of discomfort with the Chinese herbal treatments.

Comment

This was probably the first study of Chinese herbal medicine that both adhered to the principles of Chinese herbal medicine and to accepted principles of methodological rigour. The result was positive - not just positive, but with high levels of statistical significance.

Don't ask Bandolier what was in the Chinese herbal medicine, but if you want to know, a list of the 20 components of the standard treatment is to be found in the paper. We do not know whether such a medicine can be obtained commercially, but the lesson is that for some people with irritable bowel syndrome, Chinese herbal remedy may offer a welcome amelioration of symptoms.

Reference:

A Bensoussan, NJ Talley, M Hing et al. Treatment of irritable bowel syndrome with Chinese herbal medicine. A randomized controlled study. JAMA 1998 280: 1585-1589.

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