Prevalence and Clinical Features of Incidental Inflammatory Bowel Disease Identified During Screening and Surveillance Colonoscopy.

BACKGROUND

Inflammatory bowel disease (IBD) can be detected in the absence of clinical symptoms.

AIMS

To determine the prevalence of incidental IBD in patients undergoing screening colonoscopy and to explore its clinical features and long-term outcomes.

METHODS

We conducted a retrospective cohort study that included all asymptomatic adults who underwent colonoscopy for colorectal cancer screening or polyp surveillance between 2009 and 2023 in a large health system. Incidental IBD was defined as endoscopic and histologic findings consistent with the disease in the absence of symptoms. Clinical characteristics and outcomes were collected.

RESULTS

Among 40,573 patients who underwent colonoscopy, 60 were diagnosed with incidental IBD: 40 with Crohn's disease (CD), 10 with ulcerative colitis (UC), and 10 with IBD-unclassified (IBD-U). Mean age at diagnosis was 54.6 years for CD, 52.8 years for UC, and 55.7 years for IBD-U, with an overall female predominance (53%). Most CD patients had ileal involvement (98%) and inflammatory behavior (98%), and 60% of UC patients had extensive disease. After a mean follow-up period of 27.9 ± 34.7 months, 10 (16.7%) patients developed symptoms, and 5 (8.3%) initiated therapy, mostly after symptom onset. No hospitalizations or surgeries were reported.

CONCLUSION

The prevalence of incidental IBD detected during colorectal cancer screening is low (0.15%), with 20% of CD and 20% of UC cases progressing to symptomatic disease. Incidental IBD has a mild disease course with a low likelihood of progression to complications.