Acute idiopathic pancreatitis is associated with more aggressive disease course in Crohn's disease but not in ulcerative colitis.

Purpose: Patients with inflammatory bowel disease (IBD), whether Crohn's disease (CD) or ulcerative colitis (UC), have an increased risk of acute pancreatitis. The prognostic value of diagnosing acute idiopathic pancreatitis in patients with IBD is not well understood.

Methods: A retrospective review of 56 patients with IBD and acute pancreatitis was conducted in a tertiary center from 2011 to 2020. Aggressive disease course was defined as (i)biologic change, (ii)biologic dose escalation, or (iii)IBD-related surgeries occurring within 1 year of acute pancreatitis diagnosis. Logistic regression modelling identified associations between covariates and an aggressive disease course.

Results: Baseline characteristics between idiopathic pancreatitis and other causes of acute pancreatitis, in both CD and UC cohorts, were similar. Idiopathic pancreatitis was significantly associated with an aggressive disease course in CD (P = 0.04). No confounding factors were associated with an aggressive disease course in CD. Idiopathic pancreatitis, however, was not associated with an aggressive disease course in UC (P = 0.35).

Conclusion: The diagnosis of acute idiopathic pancreatitis may provide a prognostic indicator of a more severe disease course in CD. No such association appears to exist with UC. To the best of our knowledge, this is the first study that identifies an association and possible prognostic value between idiopathic pancreatitis and a more severe disease course in CD. More studies with a larger sample size are needed to validate these findings, further define idiopathic pancreatitis as an extraintestinal manifestation of IBD and elucidate a clinical strategy to optimize care in patients with aggressive CD and idiopathic pancreatitis.