Sequential Crohn’s Ileitis, Ileosigmoidal Fistula, Segmental Sigmoid Polyposis, and Sigmoid Stricture: The Natural History - Abstract
Background: We have previously recognized segmental sigmoid polyps as an indicator of a fistula from Crohn’s ileitis to the sigmoid or proximal rectum.
In the course of this study we realized that many patients with this fistula had no sigmoid polyps, but the sigmoid was the site of marked inflammation and
early or late stricture formation. Furthermore, in some patients with a stricture, the fistula was not recognized until the Surgeon (or the Pathologist) dissected an
inflammatory peri-ileal and/or a peri-sigmoidal mass.
In this study we have sought to clarify the sequence of events by focusing on the segmental inflammation and stricturing of the sigmoid so that its significance
be recognized as a local complication of the ileitis and progression of its severity as opposed to arising sui generis.
Methods: From our database of more than 3000 patients with inflammatory bowel disease (IBD) at Lenox Hill Hospital we have identified 45 patients with
Crohn’s ileitis and ileo-sigmoid fistula; 24 had segmental sigmoid polyps and 18 had segmental inflammatory sigmoid strictures. The fistula was first seen by
imaging in 36 but not until resection by the Surgeon or dissection by the Pathologist in 7.
Results: The method of diagnosis forthe initial recognition of theileo-sigmoid fistula and the sigmoid stricture are presented in the Table 1. In 36 of the
45 cases the ISF was recognized by radiological imaging. 31 of the 36 required surgical intervention, not because of the fistula but because of small bowel
obstruction due to the ileitis. In 7 of the 31 (22%) the fistula was recognized only by dissection of the inflammatory ileo-sigmoid mass by the surgeon or
examination of the surgical specimen by the Pathologist. The sequence of events from the originating ileitis to the ileo-sigmoid fistula to the segmental sigmoid
polyposis and stricture with resulting sigmoid obstruction is shown in Figure 1A-E.
Conclusion: Emphasis is made on the natural history of the I-S fistula so that its recognition will lead to earlier medical management of the originating
ileitis. Furthermore it adds evidence of the recognition that the causative agent of Crohn’s disease is carried by the fecal stream.