Prevalence, Risk Factors, and Outcomes of Irritable Bowel Syndrome After Infectious Enteritis: A Systematic Review and Meta-analysis

Background & Aims Foodborne illness affects 15% of the US population each year, and is a risk factor for irritable bowel syndrome (IBS). We evaluated risk of, risk factors for, and outcomes of IBS after infectious enteritis. Methods We performed a systematic review of electronic databases from 1994 through August 31, 2015 to identify cohort studies of the prevalence of IBS 3 months or more after infectious enteritis. We used random-effects meta-analysis to calculate the summary point prevalence of IBS after infectious enteritis, as well as relative risk (compared with individuals without infectious enteritis) and host- and enteritis-related risk factors. Results We identified 45 studies, comprising 21,421 individuals with enteritis, followed for 3 months to 10 years for development of IBS. The pooled prevalence of IBS at 12 months after infectious enteritis was 10.1% (95% confidence interval [CI], 7.2−14.1) and at more than 12 months after infectious enteritis was 14.5% (95% CI, 7.7−25.5). Risk of IBS was 4.2-fold higher in patients who had infectious enteritis in the past 12 months than in those who had not (95% CI, 3.1−5.7); risk of IBS was 2.3-fold higher in individuals who had infectious enteritis more than 12 months ago than in individuals who had not (95% CI, 1.8−3.0). Of patients with enteritis caused by protozoa or parasites, 41.9% developed IBS, and of patients with enteritis caused by bacterial infection, 13.8% developed IBS. Risk of IBS was significantly increased in women (odds ratio [OR], 2.2; 95% CI, 1.6−3.1) and individuals with antibiotic exposure (OR, 1.7; 95% CI, 1.2−2.4), anxiety (OR, 2; 95% CI, 1.3−2.9), depression (OR, 1.5; 95% CI, 1.2−1.9), somatization (OR, 4.1; 95% CI, 2.7−6.0), neuroticism (OR, 3.3; 95% CI, 1.6−6.5), and clinical indicators of enteritis severity. There was a considerable level of heterogeneity among studies. Conclusions In a systematic review and meta-analysis, we found >10% of patients with infectious enteritis develop IBS later; risk of IBS was 4-fold higher than in individuals who did not have infectious enteritis, although there was heterogeneity among studies analyzed. Women—particularly those with severe enteritis—are at increased risk for developing IBS, as are individuals with psychological distress and users of antibiotics during the enteritis.