Systematic review and meta-analysis: the incidence and prognosis of post-infectious irritable bowel syndrome

Background Individual studies suggest that post-infectious irritable bowel syndrome is common, but symptoms gradually improve. Aim To review evidence for an association between intestinal infection and development of irritable bowel syndrome, assess the prognosis of post-infectious irritable bowel syndrome and explore factors that increase the risk. Methods MEDLINE (1966-2007) and EMBASE (1980-2007) databases were searched to identify the studies of post-infectious irritable bowel syndrome epidemiology. Data were extracted by two independent reviewers. Pooled odds ratios (POR) and corresponding 95% Cl for incidence of irritable bowel syndrome were estimated among the exposed and unexposed groups. Results Eighteen of 26 studies identified were eligible for inclusion. Intestinal infection was associated with increased odds of developing irritable bowel syndrome at study end (POR = 5.86; 95% Cl: 3.60-9.54). In subgroup analysis, the odds of developing irritable bowel syndrome was increased at 3 months (POR = 7.58; 95% Cl: 4.27-13.45), 6 months (POR = 5.18; 95% Cl: 3.24-8.26), 12 months (POR = 6.37; 95% Cl: 2.63-15.40) and 24-36 months (POR = 3.85; 95% Cl: 2.95-5.02). Among all studies (controlled and uncontrolled), the pooled incidence of irritable bowel syndrome at study conclusion was 10% (95% Cl: 9.4-85.6). Subjects with post-infectious irritable bowel syndrome were younger and more anxious and depressed than those without post-infectious irritable bowel syndrome. Conclusion The odds of developing irritable bowel syndrome are increased sixfold after acute gastrointestinal infection. Young age, prolonged fever, anxiety and depression are risk factors for post-infectious irritable bowel syndrome.