Single-center, retrospective, observational study. The medical records of patients who underwent colectomy and ileorectal anastomosis (IRA) for refractory Crohn's colitis between 1996 and 2016 were reviewed.

Several studies show that, although the type of disease changes in a statistically significant way after 5 years from diagnosis, overall, a follow-up of more than 10 years indicates that the disease remains unchanged in about 85% of patients. Studies show that up to 70% of patients with Crohn's disease (CD) undergo surgery at least once in their lifetime. In colon Crohn's disease, the cumulative risk of surgery 10 years after diagnosis is lower compared to ileal Crohn's disease. For patients with extensive colitis who do not respond to medical therapy, total colectomy with ileorectal anastomosis (IRA) is a safe and effective approach. Several studies in the literature have retrospectively evaluated the recurrence rate after colectomy and IRA in Crohn's disease-related colitis, showing reasonable recurrence rates. Furthermore, several studies have highlighted that rectal involvement and the presence of perianal disease may be predictive factors for recurrence in Crohn's colitis treated with colectomy and ileorectal anastomosis (IRA). Ileal involvement in colectomy in patients with Crohn's colitis appears to be associated with a higher risk of recurrence in the small intestine and failure of the IRA. Our study is based on the hypothesis that, in patients with extensive and refractory Crohn's colitis but without rectal involvement or perianal disease, colectomy and IRA could instead drastically reduce the recurrence rate.

Inclusion Criteria:

• patients with Crohn's colitis who underwent colectomy and ileorectal anastomosis

Exclusion Criteria:

• none

patients with Crohn's disease who underwent colectomy and ileorectal anastomosis between 1996 and 2016, in a single IBD tertiary center