Aim: To review the optimal strategy to prevent recurrence of Crohn's disease (CD) after surgery, with particular emphasis on the risk factors that predict postoperative recurrence, methods of monitoring for recurrence and medications used to prevent postoperative recurrence.

Method: MEDLINE and the Cochrane Library were searched for clinical trials and meta-analyses that studied postoperative recurrence and prophylactic medications in CD.

Results: The most significant factor that predicted postoperative recurrence was patient smoking status. Smokers had an increased risk of recurrence (odds ratio = 2.15; 95% confidence interval (CI) = 1.42-3.27). Similarly, perforating CD appeared to be associated with a higher recurrence rate compared with nonperforating CD (hazard ratio = 1.50; 95% CI = 1.16-1.93). The optimal monitoring strategy for postoperative recurrence has yet to be established. Nonetheless, ileocolonoscopy is considered to be the gold standard. Noninvasive imaging techniques including contrast ultrasonography and capsule endoscopy appear to be useful for postoperative monitoring. A number of meta-analyses found that mesalazine, nitroimidazole antibiotics and purine analogues (azathioprine/6-mercaptopurine) significantly reduced the risk of postoperative recurrence when compared with placebo. Additionally, recent randomized controlled trials have suggested that an early intervention with infliximab is likely to prevent recurrence after ileocolonic resection. Likewise, in prospective studies, biological therapy (infliximab/adalimumab) reduced clinical and endoscopic CD activity in patients with early endoscopic recurrence after surgery.

Conclusion: Although additional evidence is necessary, endoscopic monitoring and treatment step-up should be used to prevent postoperative recurrence of CD.