Background and aims: Bacterial gastroenteritis has been known as a risk factor of irritable bowel syndrome (IBS). Several risk factors of post-infectious IBS (PI-IBS) have been documented. The aims of this study were to verify the role of bacterial gastroenteritis in the development of IBS and the risk factors for the development of PI-IBS. The clinical course of PI-IBS was also investigated.
Methods: We recruited 143 patients with shigellosis during its outbreak and 113 controls. Both groups were followed up for 12 months. Bowel symptoms were evaluated by use of questionnaires at 3, 6 and 12 months after the initial recruitment.
Results: Complete data were obtained from 101 patients (70.6%) and 102 healthy controls (90.3%). At 12 months, 15 patients and six controls had IBS (adjusted OR; 2.9, 95% CI; 1.1-7.9). Of the 15 patients, five had IBS symptoms consistently for 12 months, three did not have IBS symptoms initially and seven had fluctuating bowel symptoms. The duration of diarrhea was an independent risk factor of PI-IBS.
Conclusions: Bacterial gastroenteritis is a risk factor of IBS and the duration of diarrhea as the index of severity of initial illness is an independent risk factor of PI-IBS. The clinical course of PI-IBS is variable over the 1 year of follow-up.