Does bacterial gastroenteritis predispose people to functional gastrointestinal disorders? A prospective, community-based, case-control study.

Objectives: Irritable bowel syndrome (IBS) might develop after gastroenteritis. Most previous studies of this relationship have been uncontrolled, and little is known regarding other functional gastrointestinal disorders (FGIDs) after gastroenteritis. The primary aim of this study was to determine the frequency of IBS, functional dyspepsia, or functional diarrhea 6 months after bacterial gastroenteritis.

Methods: This was a prospective, community-based, case-control study. Cases had proven bacterial gastroenteritis, and controls were community-based. FGIDs were diagnosed with the use of self-completed Rome II modular questionnaires administered at baseline, 3, and 6 months. Subjects with prior FGIDs were excluded. The primary endpoint was the presence of one of the three specific FGIDs at 6 months.

Results: A total of 500 cases and 705 controls were identified. Of the 500 cases, 265 (53%) consented, but only 128 cases and 219 community controls who consented were eligible. At 6 months, 108 cases and 206 controls returned the questionnaire. FGIDs were diagnosed in significantly more cases (n = 27, 25%) than controls (n = 6, 2.9%) (OR = 11.11, 95% CI = 4.42-27.92). IBS was diagnosed in 18 cases (16.7%) and four controls (1.9%) (OR = 10.1, 95% CI = 3.32-30.69); functional diarrhea in six cases (5.6%) and no controls. Functional dyspepsia was uncommon in both cases and controls. Similar findings were found at 3 months, with 29% of cases and 2.9% of controls having an FGID.

Conclusions: Symptoms consistent with IBS and functional diarrhea occur more frequently in people after bacterial gastroenteritis compared with controls, even after careful exclusion of people with pre-existing FGIDs. The frequency is similar at 3 and 6 months. Our findings support the existence of postinfectious IBS and give an accurate estimate of its frequency.