BackgroundInflammatory bowel disease (IBD) is a chronic condition characterized primarily by inflammation of the gastrointestinal tract. Pericarditis is a rare but important extraintestinal manifestation of IBD that is poorly understood, yet is associated with significant morbidity. The objectives of this study were to identify the factors associated with pericarditis in IBD, and associated complications. MethodsHospitalized adult patients (aged ≥ 18 years) with a diagnosis of acute pericarditis in the IBD cohort, 2011-2020, were identified from the National Inpatient Sample using codes from the International Classification of Diseases (revision 9 or 10). Multivariable logistic regression was performed to identify clinical factors associated with pericarditis among IBD patients, and in-hospital mortality. ResultsDuring the period 2011-2020, among 3,236,747 IBD patients, 9113 (0.28%) had pericarditis, with a mean patient age of 54.08 ± 0.48 years, with 53.1% being female. Patients with IBD and coexisting diagnoses of systemic lupus erythematosus (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.03-2.15, P = 0.033), rheumatoid arthritis and/or collagen vascular disorders (OR 1.75, 95% CI [1.41-2.17], P < 0.001), or postcardiotomy syndrome (OR 67.13, 95% CI [30.08-149.80], P < 0.001), were each associated with a higher risk of pericarditis. Compared to IBD patients without pericarditis, patients with IBD and pericarditis had an increased associated incidence of inpatient mortality (OR 1.65, 95% CI [1.25-2.18], P < 0.001). ConclusionsPericarditis is an uncommon but important manifestation of IBD. The presence of a concomitant autoimmune condition leads to a higher likelihood of developing pericarditis among IBD patients, and IBD patients who develop pericarditis have a higher incidence of inpatient mortality, compared to that among IBD patients without pericarditis. Special attention should be given to this specific subgroup, to prevent adverse complications.