Clinical Decision Making in Inflammatory Bowel Disease Mimics: Practice Management from Inflammatory Bowel Disease LIVE

Background: Since 2009, inflammatory bowel disease (IBD) specialists have utilized "IBD LIVE,"a weekly live video conference with a global audience, to discuss the multidisciplinary management of their most challenging cases. While most cases presented were confirmed IBD, a substantial number were diseases that mimic IBD. We have categorized all IBD LIVE cases and identified "IBD-mimics"with consequent clinical management implications. Methods: Cases have been recorded/archived since May 2018; we reviewed all 371 cases from May 2018-February 2023. IBD-mimics were analyzed/categorized according to their diagnostic and therapeutic workup. Results: Confirmed IBD cases made up 82.5% (306/371; 193 Crohn's disease, 107 ulcerative colitis, and 6 IBD-unclassified). Sixty-five (17.5%) cases were found to be mimics, most commonly medication-induced (n = 8) or vasculitis (n = 7). The evaluations that ultimately resulted in correct diagnosis included additional endoscopic biopsies (n = 13, 21%), surgical exploration/pathology (n = 10, 16.5%), biopsies from outside the GI tract (n = 10, 16.5%), genetic/laboratory testing (n = 8, 13%), extensive review of patient history (n = 8, 13%), imaging (n = 5, 8%), balloon enteroscopy (n = 5, 8%), and capsule endoscopy (n = 2, 3%). Twenty-five patients (25/65, 38%) were treated with biologics for presumed IBD, 5 of whom subsequently experienced adverse events requiring discontinuation of the biologic. Many patients were prescribed steroids, azathioprine, mercaptopurine, or methotrexate, and 3 were trialed on tofacitinib. Conclusions: The diverse presentation of IBD and IBD-mimics necessitates periodic consideration of the differential diagnosis, and reassessment of treatment in presumed IBD patients without appropriate clinical response. The substantial differences and often conflicting treatment approaches to IBD versus IBD-mimics directly impact the quality and cost of patient care.