Hypnosis for irritable bowel syndrome: the quest for the mechanism of action.

Irritable bowel syndrome (IBS) is a very common condition in the Western part of the world, and it accounts for a large proportion of the workload of a gastroenterologist. Unfortunately, the pathogenesis and pathophysiology of the syndrome are incompletely understood, and the treatment options are limited. However, hypnotherapy is one treatment option that has proven to be very useful in IBS. The mechanisms of action explaining why hypnosis is effective for IBS are not altogether known, but recent studies have shed some light on this issue. These studies, and what can be learned from them about how hypnosis impacts IBS, are reviewed in this article. Hypnosis may affect IBS partly through changes in colorectal sensitivity and improvement in psychological factors. The effects on GI motility and the autonomic nervous system are less clear and need further evaluation.