Rarity of fistulas in Crohn's disease of the jejunum

: To compare the fistulizing tendency of Crohn's disease of the jejunum versus the ileum, we reviewed the records of 1,920 patients with Crohn's disease admitted to the Mount Sinai Hospital between 1960 and 1994. Fifty-eight of the cases (3%) had jejunal involvement. Of these 58 patients, six (10%) had fistulas originating from the jejunum. Four of the cases of jejunal fistulas came from a subgroup of 41 patients who had both jejunum and distal ileum involvement (10%); by contrast, there were 12 cases of ileal fistulas in the same subgroup (29%, p = 0.05). As another measure of the relative rarity of jejunal versus ileal fistulization, there were 252 cases of ileal fistulas in our overall series among 723 patients with distal ileal Crohn's disease (34%), compared with the 10% (six of 60) incidence of jejunal fistulization (p = 0.001). Only 50% (316) of our cases of jejunal fistulization were spontaneous, compared with 86% of a random sample (43 of 50) from our 252 cases of fistulas with ileitis. The development of jejunal fistulas did not appear to depend upon the presence of stricturing; they were nearly as common among nonstricturing cases (two of 27, 7%) as among stricturing cases (four of 31, 13%; p = NS). The inherent proclivity of Crohn's disease to fistulize thus appears to increase with a progressively distal location in the gastrointestinal tract.