Chinese herb mix ineffective for irritable bowel

NEW YORK (Reuters Health) - A centuries-old Chinese herbal medicine prescribed for treating irritable bowel syndrome (IBS) appears to be ineffective, Hong Kong researchers report.

But because the medicine is so complex, consisting of 11 herbs, it may be worthwhile to test other formulations in these patients, the researchers conclude.

Dr. Wai K. Leung of The Chinese University of Hong Kong and colleagues compared the formulation with placebo in a group of 119 patients with IBS primarily characterized by diarrhea. All had a diagnosis of IBS that had been verified by Western criteria and by the rules of traditional Chinese medicine.

In Chinese medicine, Leung and his team note, diarrhea-predominant IBS is thought to be due to "stagnation of liver energy attacking the spleen resulting in dysfunction of the transportation and transformation function of the spleen." The remedy for these symptoms is the Tong Xie Yao Fang formulation, which dates back to the 1600s.

In the study, patients dissolved the herbal remedy or a placebo herbal mix in hot water and took it twice daily for eight weeks.

After the 8-week treatment period and eight weeks after treatment ended, there was no difference between the two groups in IBS symptoms or quality of life.

However, the researchers note, the placebo effect seen in the study -- with 46.6 percent of patients reporting improvement in their symptoms after four weeks of treatment -- was higher than reported in most other IBS studies.

"While Chinese herbal formulations usually comprise multiple herbs, more work may have to be done to characterize the proper preparation to be used in the treatment of IBS patients," the researchers write.

"A properly controlled clinical trial is essential in this aspect because of the high placebo response of Chinese patients to traditional Chinese medicine," they add.

SOURCE: American Journal of Gastroenterology, July 2006.