An evidence-based approach to studies of the natural history of gastrointestinal diseases: Recurrence of symptomatic Crohn's disease after surgery  James D. Lewis, Philip Schoenfeld, Gary R. Lichtenstein  Clinical Gastroenterology and Hepatology  Volume 1, Issue 3, Pages 229-236 (May 2003) DOI: 10.1016/S1542-3565(03)70040-8 Copyright © 2003 American Gastroenterological Association Terms and Conditions

Fig. 1 Survival curve corresponding to the hypothetical data presented in Table 1. Note that no patient is observed to require reoperation during the first 5 years while the reoperation rate was 100% by 10 years of follow-up. Clinical Gastroenterology and Hepatology 2003 1, 229-236DOI: (10.1016/S1542-3565(03)70040-8) Copyright © 2003 American Gastroenterological Association Terms and Conditions

Fig. 2 Survival curves regarding recurrence after primary colectomy in 394 patients with Crohn's colitis, (log rank test, P< 0.01). Slant-dashed line indicates colectomy and ileostomy (n = 65); thin solid line indicates proctocolectomy and ileostomy (n = 89); wide solid line indicates colectomy with ileorectal anastomosis (n = 106); dashed line indicates segmental colonic resection (n = 134). Reprinted with permission from Bernell O, Lapidus A, Hellers G. Recurrence after colectomy in Crohn's colitis. Dis Colon Rectum 2001;44:647-654. Clinical Gastroenterology and Hepatology 2003 1, 229-236DOI: (10.1016/S1542-3565(03)70040-8) Copyright © 2003 American Gastroenterological Association Terms and Conditions