PSYCHOLOGICAL AND PHYSICAL STRESS INDUCE DIFFERENTIAL-EFFECTS ON HUMAN COLONIC MOTILITY

Objective: Stress modulates gut function, but whether the type of stre ssor influences colonic motor activity is unclear. The motor patterns and regional variations are also poorly understood. Our aim was to det ermine the effects of psychological and physical stress on colonic mot ility. Methods: Ambulatory colonic manometry was performed by placing a six-sensor probe up to the mid-transverse colon, without sedation, i n 12 healthy subjects. Five hours later, a dichotomous listening test (psychological stress) was performed, which was preceded by listening to a narrative passage (control); recovery entailed listening to relax ing music (1 h each). Subsequently, intermittent hand immersion in col d (4 degrees C) water (physical stress) was performed, preceded by han d immersion in warm (37 degrees C) water (1/2-h each). Colonic pressur e activity and cardiovascular responses mere measured throughout the s tudy. Results: When compared with the control period, both stressors i nduced a greater number of pressure waves (p < 0.05), and the area und er the curve (p < 0.01), but only physical stress increased (p < 0.05) pulse rate and blood pressure. There were no regional differences in colonic motility. During recovery, the motor activity returned to base line after physical stress, but remained high after psychological stre ss. Psychological stress induced more (p < 0.05) propagated contractio ns, whereas physical stress induced more (p < 0.05) simultaneous contr actions. Conclusions: Both stressors enhanced colonic motor activity, but psychological stress induced a prolonged response with propagated activity and without appreciable autonomic response. Thus, colonic mot or responses may vary depending on the stressor. (Am J Gastroenterol 1 998;93: 985-990. (C) 1998 by Am. Cell. of Gastroenterology).