Colonic Crohn's Disease Is Associated with Less Aggressive Disease Course Than Ileal or Ileocolonic Disease

The literature on disease characteristics of colonic Crohn's disease (CD) is sparse, especially from Asia, where the burden of inflammatory bowel disease is on the rise. The present study aims to describe the disease characteristics of colonic CD, and compare it with that of ileal/ileocolonic disease.

This retrospective study included adult patients of CD (diagnosed by standard criteria, follow-up duration > 6 months) on follow-up between August 2004 and January 2016. The disease location was classified by Montreal classification. The data were recorded on demographic characteristics, smoking status, disease phenotype, disease course, treatment received, hospitalization and surgeries.

Of 406 CD patients, 123 had colonic [mean age (at onset) 30.4 ± 13.2 years, 59.3% males] and 265 had ileal/ileocolonic disease [mean age (at onset) 32.9 ± 13.8 years, 61.5% males] while 18 patients had isolated upper GI disease. The frequency of inflammatory behavior (B1 phenotype; 61.8 vs. 46.4%, p = 0.003), perianal disease (23.6 vs. 4.5%, p < 0.001), and extra-intestinal manifestation (42.3 vs. 30.2%, p = 0.019) was higher in colonic than ileal/ileocolonic CD. Though not statistically significant, requirement of atleast one course of steroid was lower in colonic CD (72.7 vs. 84.2%, p = 0.098). Although there was no difference in the frequency of hospitalization (30.1 vs. 27.1%, p = 0.45), the overall requirement for surgery was significantly lower in colonic CD (17.1 vs. 26.1%, p = 0.032) and patients with colonic disease had a lower cumulative probability of first surgery in the first 10 years of follow-up [Hazard ratio 0.556 (95% CI 0.313-0.985), p = 0.045].

Colonic CD was associated with less aggressive disease behavior and lower requirement of surgery as compared to ileal/ileocolonic CD.