Inflammatory bowel disease uncovered in fecal immunochemical test positive patients in a Canadian provincial colon cancer screening program

Abstract Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition that usually affects younger adults but has a second incidence peak in the older population. Although diagnosis of IBD is driven by symptoms, some patients are asymptomatic and incidentally discovered while participating in colon screening program (CSP). We aimed to identify the incidence and outcome of IBD in fecal immunochemical test (FIT) positive patients in the British Columbia CSP. We conducted a retrospective chart review of patients who had colonoscopies for positive FIT and were found to have colitis based on endoscopic and histological assessment. Of 93,994 patients who underwent screening colonoscopy for positive FIT between 2009 and 2017, 608 (0.6%) were found to have colitis. From 11 CSP sites, 191 patients met the inclusion criteria. 58 patients (30.4%) were diagnosed with ulcerative colitis, 109 (57.1%) with Crohn’s disease (CD), and 24 (12.6%) with IBD unclassified. 124 patients (64.9%) received treatment, of which 34 (17.8%) received biologics and 4 (2.1%) required surgery. Our study demonstrated a clinically significant incidence of IBD, with novel finding of CD predominance, within a Canadian provincial CSP. Further research is needed to guide management of older patients with varying rates of IBD progression after incidental diagnosis.