Effect of faecal stream diversion on recurrence of Crohn's disease in the neoterminal ileum

Aphthous lesions recur in the neoterminal ileum within the first few months after curative resection of the distal ileum in patients with Crohn's disease. These lesions do not originate from microscopic disease that is already present at the time of surgery. To investigate the importance of faecal stream in the pathogenesis of recurrent Crohn's lesions, we have studied 5 patients with Crohn's disease who had ileal resection. After curative resection and ileocolonic anastomosis, a diverting terminal ileostomy was constructed 25-35 cm proximal to the anastomosis thereby excluding the neoterminal ileum, the anastomosis, and the colon from intestinal transit. After six months of exclusion, endoscopy of the ileocolon was undertaken and biopsy specimens were taken. Transit was then restored. Six months after reanastomosis further biopsy specimens were taken. These patients were compared with a control group of 75 patients with Crohn's disaease who underwent a one-step ileal resection and ileocolonic anastomosis. None of the 5 patients had endoscopic lesions in the neoterminal ileum after six months of exclusion and biopsies did not show inflammatory changes characteristic of Crohn's disease. By contrast, 53 of 75 patients with one-step surgery had endoscopic recurrence in the neoterminal ileum within six months of surgery. All 5 patients had an important recurrence of disease, both endoscopically and histologically, at ileocolonoscopy six months after reanastomosis. Our findings strongly support the view that recurrence of Crohn's disease in the neoterminal ileum after curative ileal resection is dependent on faecal stream.