Whorwell et al's "Physiological effects of emotion: assessment via hypnosis".
«Assessment of the physiological effects of physical and emotional stress has been hampered by a lack of suitable laboratory techniques. Since hypnosis can be used safely to induce specific emotional states of considerable intensity, we studied the effect on distal colonic motility of three hypnotically induced emotions (excitement, anger, and happiness) in 18 patients aged 20-48 years with irritable bowel syndrome. Colonic motility index was reduced by hypnosis on its own (mean change 19.1; 95% CI 0.8, 37.3; P<0.05) and this change was accompanied by decreases in both pulse (12; 8, 15) and respiration (6; 4, 8) rates (P< 0.001 for both)