Clinical patterns over time in irritable bowel syndrome: symptom instability and severity variability

Abstract

Objectives: The clinical course of irritable bowel syndrome (IBS) remains poorly known. In 209 IBS patients meeting Rome II criteria (137 females and 72 males) we evaluated: (1). changes in frequency and intensity of abdominal pain/discomfort, abnormal number of bowel movements, loose or watery stools, defecatory urgency, hard or lumpy stools, straining during bowel movements, and feeling of incomplete evacuation); (2). use of resources, HRQoL, and psychological well being.

Methods: Observational, prospective, multicenter study. Symptoms were registered in a diary over two 28-day periods with an interval of 4 wk; direct resource use and indirect costs were noted weekly. Three HRQoL questionnaires were administered.

Results: High-intensity symptoms were present on more than 50% of the days. Sixty-one percent were classified in the same IBS subtype on both occasions (kappa= 0.48), while 49% had the same symptom predominance and intensity (kappa= 0.40). The greatest instability was observed among diarrhea (D-IBS) and constipation (C-IBS) subtypes: only 46% and 51% remained in the same pattern with a tendency to shift to alternating diarrhea/constipation subtype (A-IBS); however, practically no patient changed from D-IBS to C-IBS, or vice versa. The most reliable symptom characteristic was frequency, followed by intensity and number of episodes. Symptom frequency and intensity were directly related to resource use and HRQoL impairment.

Conclusions: IBS symptoms are instable over time and variables in intensity. Many patients with D-IBS or C-IBS move to A-IBS; however, shift from D-IBS to C-IBS, or vice versa, is very infrequent.