S333 Microscopic Colitis and Risk of Acute and Chronic Pancreatitis: A United States Retrospective Cohort Study

Introduction: Microscopic colitis is a chronic inflammatory disorder of the colon that typically presents with watery diarrhea and abdominal pain. A recent Swedish study by Bergman et al. demonstrated an increased risk of acute pancreatitis in patients with microscopic colitis. However, this novel association has not been studied in the United States population. In this single center retrospective cohort study we further investigate the association between microscopic colitis and acute and chronic pancreatitis. Methods: All patients with biopsy proven microscopic colitis from 2007-2024 at our center were included in this study (n = 382). Each chart was reviewed to evaluate for a diagnosis of acute or chronic pancreatitis. Acute pancreatitis was defined using standard diagnostic criteria, while chronic pancreatitis was defined by imaging findings on computed tomography, magnetic resonance imaging, or endoscopic ultrasound that lead to a chart diagnosis of chronic pancreatitis. For all patients demographic history, comorbidities, medications, endoscopy findings, biopsy results, and acute and chronic pancreatitis diagnosis was collected. For comparison, a cohort of patients with irritable bowel syndrome with diarrhea (IBS-D) was obtained and the same data points were collected through retrospective chart review. A matched analysis on the basis of age and sex was also performed using treatment-control propensity score matching. Results: Of 556 total patients, 68.6% (n = 382) were diagnosed with microscopic colitis and 31.4% (n = 174) were diagnosed with IBS-D. Nine patients (2.4%) with microscopic colitis had a diagnosis of acute pancreatitis compared to 5 patients (2.9%) in the IBS-D group (P = 0.92). Regarding chronic pancreatitis, the microscopic colitis group had 6 with chronic pancreatitis (1.6%) compared to the IBS-D group who had zero with chronic pancreatitis (P = 0.18). Similar findings which did not reach statistical significance were seen in the matched cohort (P = 0.45). Conclusion: In this single center US study, there was no significant difference in the risk of acute or chronic pancreatitis in microscopic colitis patients compared to IBS-D patients. However, the microscopic colitis cohort had 5 patients (2.9%) with chronic pancreatitis compared to zero patients with chronic pancreatitis in the IBS-D cohort. Further studies are needed to see if the inflammatory milieu of microscopic colitis is associated with an increased risk of acute and chronic pancreatitis.