Hypnosis treatment for severe irritable bowel syndrome: investigation of mechanism and effects on symptoms.

A team of researchers from UNC Chapel Hill, interested in learning how hypnosis manages to improve irritable bowel syndrome (IBS), designed two studies that measured and separated out possible physiological mechanisms from psychological ones. Patients with severe IBS received seven biweekly hypnosis sessions and used hypnosis audiotapes at home. Rectal pain thresholds and smooth muscle tone were measured with a barostat before and after treatment in 18 patients in one study, and treatment changes in autonomic functions such as heart rate, blood pressure, skin conductance, finger temperature, and forehead electromyographic activity were assessed in 24 patients in the second study. Somatization, anxiety, and depression were also measured. All central IBS symptoms improved substantially from treatment in both studies. Rectal pain thresholds, rectal smooth muscle tone, and autonomic functioning (except sweat gland reactivity) were unaffected by hypnosis treatment. However, somatization and psychological distress showed large decreases. The study concludes that hypnosis improves IBS symptoms through reductions in psychological distress and somatization, and that percieved improvements were unrelated to changes in the physiological parameters measured.

Citation: Palsson OS, Turner MJ, Johnson DA, Burnelt CK, Whitehead WE. Hypnosis treatment for severe irritable bowel syndrome: investigation of mechanism and effects on symptoms. Dig Dis Sci 2002 Nov;47(11):2605-14