Irritable bowel syndrome: the influence of psychological factors on the symptom complex.

A 5 yr follow up of Irritable Bowel Syndrome (IBS) is described. With the notable exception of abdominal pain, gastrointestinal symptoms changed little over this period, and were unrelated to the overall improvement in wellbeing reported by 65% of patients. The anxiety ratings of the improved and unimproved groups at initial assessment and 5 yr later are considered. There was a persisting trend towards higher ratings in those who did not improve, and an exaggeration of this trend after 5 yr, which owed more to a reduction in anxiety in those who improved than to an increase in the anxiety ratings of those who did not. There was no evidence that depression ratings behaved similarly. We suggest that anxiety may be more important in the maintenance of the IBS symptom complex, and depression more important in determining intercurrent fluctuations in perceived distress and illness behaviour in response to adverse life events.