High Incidence of Recurrent Crohn's Disease Following Colectomy for Ulcerative Colitis Revealed with Long Follow-Up.

Background And Aims: Ulcerative colitis (UC) patients with progression of their disease despite optimized medical therapy may warrant "curative" proctocolectomy with end ileostomy or ileo-anal pouch (IPAA) anastomosis. The aim of our study was to assess the incidence of later recurrent ileitis that lead to altering the initial diagnosis to Crohn's disease (CD).

Methods: A retrospective analysis was conducted on the inflammatory bowel disease database at Lenox Hill Hospital. The database consisted of patients that were diagnosed with UC or CD based on clinical assessment, endoscopic appearance, gross and histological examination, and imaging between 1960 and 2015. The post-colectomy follow-up period was at least 10 years. Recurrent disease was classified by evidence of transmural inflammation in the distal ileum, fistulizing disease, or stricturing disease.

Results: From our IBD database, we identified 128 patients who underwent elective or urgent colectomy with the preoperative diagnosis of UC. Thirty-two (25%) had either an IPAA or end ileostomy with documented recurrence of inflammation in the small bowel mucosa consistent with CD. There was no significant difference between the type of surgical approach and the chance of recurrent disease (p = .20). The average time to clinically significant recurrence was 5 years.

Conclusion: The incidence of recurrent CD following colectomy for ulcerative colitis, when followed postoperatively for an average of 20 years, was 25%, considerably more than previously reported. Patients who come to colectomy for ulcerative colitis and are followed for at least 10 years show a high incidence of recurrent Crohn's disease in the ileostomy or ileo-anal pouch. Extended follow-up should be included in patients coming to colectomy for ulcerative colitis before they should be considered cured of their disease.