Abstract

Background/Aims
We performed this study to investigate the incidence and natural history of perianal fistulas in Korean patients with Crohn's disease (CD). Methods: A total of 546 patients diagnosed with CD at Asan Medical Center were included. Results: Perianal fistulas occurred in 265 patients (48.5%), with 355 episodes. Eighty-two patients (15.0%) initially presented with perianal fistulas in the absence of other symptoms suggestive of CD. Out of 265 patients who developed perianal fistulas, 205 (77.4%) presented with perianal fistulas before, or at the time of, the diagnosis of CD. The cumulative incidence of perianal fistulas at 1, 5, 10, 20 years was 40.7%, 48.2%, 55.3% and 62.1%, respectively. Medical treatment was done in 30.7%, and surgery in 80.8% of perianal fistulas. The remission rate was 23.9% with medical treatment, and 83.6% with surgery. At least 1 recurrent fistula occurred in 77 patients (29.1%). The cumulative recurrence rate of perianal fistulas at 1, 5, 10, 20 years was 10.1%, 26.9%, 42.4% and 68.8%, respectively. Conclusions: The incidence of perianal fistulas in Korean patients with CD appears to be higher than that of Western patients. Also, the proportion of patients who develop perianal fistulas before the diagnosis of CD is very high. Therefore, we should consider the possibility of CD in patients with perianal fistulas to manage them properly, and thereby to reduce there complications. (Intestinal Research 2006;4:22-31)

• Keywords: Crohn's disease, Perianal fistula, Incidence