Increased incidence and recurrence rates of acute diverticulitis in patients with irritable bowel syndrome

Aim Acute diverticulitis (AD) is commonly diagnosed in outpatient and emergency departments and is associated with severe complications such as perforation and fistula. Symptoms of irritable bowel syndrome (IBS), such as abdominal pain, constipation and diarrhoea, are also common with AD. This study aimed to evaluate the strength of a possible association between IBS and AD. Method This retrospective study analysed records from Taiwan's National Health Insurance Research Database and involved a total of 25 810 patients, including 12 905 IBS patients diagnosed between 2000 and 2012. The IBS and non-IBS cohorts were matched by propensity score for age, gender, comorbidities and medication, then compared for confounding variables by the chi-square test or Student'st-test. The association between AD and IBS was determined using Cox proportional hazards models. Kaplan-Meier curves assessed the cumulative incidence of AD in IBS patients. Results The overall incidence of AD was 3.95-fold higher in the IBS cohort than in the non-IBS cohort (63.34vs16.02 per 100 000 person-years, respectively) and IBS was an independent risk factor for subsequent diagnosis of AD in multivariate Cox proportional hazards regression model adjusted hazards ratio (aHR = 3.84, 95% CI = 2.29-6.44,P < 0.001) and Kaplan-Meier (log-rank test,P < 0.001) analysis. IBS was also associated with a high recurrence rate of AD (aHR = 8.30, 95% CI = 1.07-64.30,P = 0.04). Conclusion The epidemiological evidence in this study demonstrates that patients with IBS are associated with a higher incidence of AD and also its recurrence.