Clinical characteristics and long-term disease course in patients with Crohn's disease as diagnosed by video capsule endoscopy: a multicenter retrospective matched case-control study.

Background/aims: Video capsule endoscopy is rarely used to diagnose Crohn's disease in patients with negative ileocolonoscopy or cross-sectional image findings. We evaluated clinical characteristics and long-term outcomes of these rare cases.

Methods: This multicenter study included patients with Crohn's disease from 3 tertiary hospitals from January 2007 to October 2022. Patients with normal findings on ileocolonoscopy and computed tomography (CT)/magnetic resonance (MR) enterography but had ulcerations at the small bowel detected by video capsule endoscopy were included. The controls were patients with abnormal findings on endoscopy or CT/MR enterography. Controls were case-matched in a ratio of 3:1 for sex, calendar year of diagnosis, and age at diagnosis.

Results: Among 3,752 patients, 24 (0.6%) were diagnosed with Crohn's disease using video capsule endoscopy findings. The disease location (P< 0.001) and behavior at diagnosis (P= 0.013) of the cases significantly differed from that of controls. The perianal fistula modifier (25.0% vs. 33.3%, P= 0.446) did not differ significantly between the 2 groups. Initial disease activity and C-reactive protein and fecal calprotectin levels were significantly lower in cases versus controls. The median Lewis score was 838 (interquartile range, 393-1,803). Over 10 years of follow-up, the cases showed significantly lower cumulative risk of complicated behavior, biologics use, Crohn's disease-related hospitalization, and surgeries (log-rank test P< 0.05).

Conclusions: Patients with Crohn's disease whose lesions were observed only by video capsule endoscopy were rare, and exhibit different clinical characteristics and a more favorable long-term disease course compared to those who were conventionally diagnosed.