Psychological and physiological responses to postprandial mental stress inwomen with the irritable bowel syndrome

Objective: To investigate the psychological (affective and symptomatic) and physiological (autonomic and cortisol) responses to postprandial mental st ress in women with irritable bowel syndrome (IBS). It was hypothesized that patients with IBS would show exaggerated autonomic and cortisol responses to the psychological stressor and that the stressor would enhance gastroint estinal symptoms, Method: Twenty-four women with IBS and 20 healthy women p articipated in the two-day study protocol. Both days were identical, with t he exception that on one day, a stressful mental task was completed after i ngestion of a standard meal. Heart rate variability, cortisol, affective, a nd symptomatic responses were measured before and after application of the stressor. Results: Patients with IBS demonstrated increased negative affect at baseline and in response to the stressor. Gastrointestinal symptoms wer e not affected by the stressor. Appraisal of the stressor by patients with IBS was not different from that of controls. There were no group difference s in the autonomic response to the stressor. There was no overall cortisol response to the stressor in either group. Conclusions: Patients with IBS re spond with greater negative affect to postprandial psychological stress as well as to food intake alone, and they can be distinguished from controls o n the basis of self-report data. Patients with IBS cannot be differentiated from controls on the basis of the pattern of changes in sympathetic activa tion after the mental stressor, The stressor used in this study did not eli cit a cortisol response in either group.