Psychological and physical stress induce differential effects on human colonic motility.

OBJECTIVE: Stress modulates gut function, but whether the type of stressor influences colonic motor activity is unclear. The motor patterns and regional variations are also poorly understood. Our aim was to determine the effects of psychological and physical stress on colonic motility. METHODS: Ambulatory colonic manometry was performed by placing a six-sensor probe up to the mid-transverse colon, without sedation, in 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 relaxing music (1 h each). Subsequently, intermittent hand immersion in cold (4 degrees C) water (physical stress) was performed, preceded by hand immersion in warm (37 degrees C) water (1/2-h each). Colonic pressure activity and cardiovascular responses were measured throughout the study. RESULTS: When compared with the control period, both stressors induced a greater number of pressure waves (p < 0.05), and the area under 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 baseline after physical stress, but remained high after psychological stress. Psychological stress induced more (p < 0.05) propagated contractions, whereas physical stress induced more (p < 0.05) simultaneous contractions. CONCLUSIONS: Both stressors enhanced colonic motor activity, but psychological stress induced a prolonged response with propagated activity and without appreciable autonomic response. Thus, colonic motor responses may vary depending on the stressor.

Psychological aspects of irritable bowel syndrome: comparisons with inflammatory bowel disease and nonpatient controls.

Patients with irritable bowel syndrome (IBS) (n = 121) were compared to 46 patients with inflammatory bowel disease (IBD), and to 45 nonpatient controls on a variety of psychological tests and on symptomatology. The most consistent finding was the ordering of group psychological test means such that, on 11 of 14 measures, IBS patients scored higher than IBD patients, who in turn scored higher than the nonpatient controls. The two patient groups differed significantly only on measures of anxiety with the IBS patients scoring significantly higher on all three measures. IBS patients also reported significantly more severity of abdominal pain than the IBD patients; while IBD patients reported more episodes of diarrhea, they did not rate them as significantly more severe than did the IBS patients. Various other parameters of the IBS population are also explored and implications for treatment and future study are discussed.

Prediction of outcome from cognitive-behavioral treatment of irritable bowel syndrome.

The presence of a diagnosable Axis I psychiatric disorder predicted significantly (P less than 0.001) lower likelihood of significant improvement among 90 irritable bowel syndrome patients given cognitive and behavioral treatments to help the disorder. Other psychological tests, including the MMPI, BDI, STAI, as well as demographic variables, failed to yield significant prediction.

Two controlled evaluations of multicomponent psychological treatment of irritable bowel syndrome.

We report two controlled comparisons of a previously validated multicomponent (relaxation, thermal biofeedback, and cognitive therapy) treatment for irritable bowel syndrome (IBS) to an ostensible attention-placebo control (pseudo-meditation and EEG alpha suppression biofeedback) and to a symptom-monitoring control. In Study 1 (n = 10 per condition) there were nonsignificant trends for the multicomponent treatment to be superior to the attention-placebo condition. In Study 2 (n = 30 per condition), we found no advantage for the multicomponent treatment over the attention-placebo condition. Subjects in both treatment conditions showed significant reductions in GI symptoms, as measured by daily symptom diaries, and significant reductions in trait anxiety and depression. The GI symptom reductions held up over a 6 month follow-up. Possible explanations for the results are explored.

The role of anxiety and depression in the irritable bowel syndrome.

Using a reliable and valid structured diagnostic interview scale (ADIS-R), and patients with careful medical characterization, we found significantly more diagnosable psychopathology, particularly anxiety disorders, among treatment seeking patients with irritable bowel syndrome than among comparable age and sex samples of treatment seeking patients with Inflammatory Bowel Disease. Significant differences were also found on the Hamilton Anxiety Rating Scale and Hamilton Rating Scale for Depression between IBS patients and the IBD patients and controls, who did not differ. Comparable levels of psychiatric disorder among parents of probands were found in all three groups. The results are consistent with Latimer's (1983) notion of IBS patients being a subclass of 'neurotics'.