Pancreatitis Preceding the Diagnosis of IBD in Children: A Retrospective Observational Study.

Background: Pancreatic involvement in inflammatory bowel diseases (IBD) is relatively common and includes a range of conditions, such as acute pancreatitis (AP), chronic pancreatitis (CP), autoimmune pancreatitis (AIP), and pancreatic exocrine insufficiency (PEI). However, pancreatitis as a precursor to IBD is not well understood and is rarely reported. Objectives: This study investigates the occurrence, etiology, severity, and recurrence patterns of acute pancreatitis (AP) prior to IBD diagnosis in pediatric patients, with the aim of improving early recognition and diagnostic approaches. Methods: This retrospective observational study was conducted between January 2019 and December 2023 at a tertiary pediatric center, including patients who developed pancreatitis prior to an IBD diagnosis. Demographic information, clinical presentation, laboratory findings, imaging results, fecal calprotectin levels, radiological tests, blood tests, and endoscopic findings were collected. Results: Among 312 pediatric IBD patients (99 with Crohn's disease (CD), 162 with ulcerative colitis (UC), 7 unclassified, and 44 with very early-onset IBD [VEO-IBD]), 11 (3.5%) had pancreatitis preceding the IBD diagnosis. All the patients showed elevated fecal calprotectin levels, and endoscopy confirmed IBD (four with CD, seven with UC). The median time from the onset of pancreatitis to the IBD diagnosis was 77 weeks (range 0-366 weeks). Conclusions: This study supports the hypothesis that pancreatitis may precede the diagnosis of IBD in some cases, acting as an early extraintestinal manifestation, as previously reported in adults. IBD should be considered in the differential diagnosis of pediatric pancreatitis, particularly in idiopathic cases. Fecal calprotectin testing should be included in the diagnostic workup for pediatric pancreatitis at both initial presentation and during follow-up. Further research is needed to better understand the mechanisms underlying this extraintestinal manifestation.