The discovery was a by product of an experiment with 18 patients with irritable bowel syndrome to measure the physiological effects of physical and emotional stress on their condition.
The research team said that hypnosis was an ideal way of viewing, under laboratory conditions, the effect on distal colonic motility by inducing the emotions of excitement, anger and happiness.
However, they discovered that hypnosis reduced colonic motility index, and lessened the pulse and respiration rates. These effects were reversed when anger and excitement were induced. Happiness also reduced motility, but not significantly.
"Although this study was not concerned with the therapeutic aspects of hypnosis, a striking observation was that induction of hypnosis led to a profound reduction in colonic motility," the research team concluded.