Postoperative recurrence of Crohn's disease is often inevitable. Certain risk factors such as smoking, young age, and a perforating disease behavior have been identified. Patients with an enhanced risk profile should be treated with mesalamine or with azathioprine, the latter of which has higher success rates. An endoscopic evaluation of the neoterminal ileum performed 6 to 12 months after surgery provides important prognostic information regarding the further clinical course of the disease and can be used as a guide to optimize medical therapy.