The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition.
Professor Jonathan Rhodes and colleagues from the United Kingdom have therefore systematically reviewed its epidemiology, pathophysiology and treatment.
|Diagnostic distinction from UC needs to exclude other conditions including ischemic colitis|
Key findings included a higher incidence in females, and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites.
The team report that diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischemic colitis, segmental colitis associated with diverticular disease and tuberculosis.
Professor Rhodes, "Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately."