Is irritable bowel syndrome more common in patients presenting with bacterial gastroenteritis? A community-based, case-control study.

OBJECTIVE: Irritable bowel syndrome (IBS) has been reported to follow infectious diarrhea. Food-borne infections affect 76 million people in the United States and 9.4 million in England per year; of these, only a small percentage of patients see their doctor, and even fewer will have stool culture confirmation. We hypothesized that patients who present to their doctor with gastroenteritis and have positive stool samples may be different from the normal population with regard to their pre-existing bowel symptoms. Our aim was to determine if patients with bacterial gastroenteritis were more likely to have prior IBS, functional dyspepsia, or functional diarrhea, compared with a control population.

METHODS: Between January, 2000 and January, 2001, subjects with stool positive bacterial gastroenteritis and control subjects from the same primary care practice were invited to participate. The main outcome measure was the presence of IBS, functional dyspepsia, or functional diarrhea diagnosed using self-report Rome II modular questionnaires.

RESULTS: A total of 217 people with recent bacterial gastroenteritis and 265 community controls consented to participate in the study. Of these, 89/217 cases and 46/265 controls had one of the functional GI disorders (OR = 3.3; 95% CI = 2.17-5.00). IBS was present in 67 cases (31%) and 26 controls (10%) (OR = 4.1; 95% CI = 2.49-6.72). There was no statistically significant difference in the presence of prior functional dyspepsia or functional diarrhea.

CONCLUSIONS: IBS is more frequent before diagnosis in people with bacterial gastroenteritis presenting to their primary care physician than in community controls. Studies that examine the rate of IBS after bacterial gastroenteritis need to carefully exclude people with prior IBS in a systematic way.