Principal changes with respect to the 2004 ECCO guidelines 

Ileocolonoscopy is recommended within the first year after surgery where treatment decisions may be affected (Statement 8C).

Thiopurines are more effective than mesalazine or imidazole antibiotics alone in post-operative prophylaxis (Statement 8F).

### 8.1 Epidemiology of post-operative Crohn's disease

In the natural history of CD, intestinal resection is almost unavoidable since about 80% of patients require surgery at some stage. Surgery is unfortunately not curative as the disease inexorably recurs in many patients. The post-operative recurrence rate varies according to the definition used: clinical, endoscopic, radiological, or surgical. It is lowest when the repeat resection rate is considered, intermediate when clinical indices are used and highest when endoscopy is employed as the diagnostic tool.1–10

Data from endoscopic follow-up of patients after resection of ileo-caecal disease have shown that in the absence of treatment, the post-operative recurrence rate is around 65–90% within 12 months and 80–100% within 3 years of the operation. The clinical recurrence without therapy is about 20–25%/year.1,10 It has been demonstrated that the post-operative clinical course of CD is best predicted by the severity of endoscopic lesions. Symptoms, in fact, appear only when severe lesions are present and it is not uncommon to observe patients with fairly advanced recurrent lesions at endoscopy who remain asymptomatic.1 For these reasons, clinical indices such as the CDAI have low sensitivity at discriminating between patients with or without post-operative recurrence.11

These data mandate strategies aimed at interrupting or delaying the natural course of post-operative recurrence. Several medications have been tried in an attempt to prevent post-operative recurrence, mostly with disappointing results. The aim of this Consensus was therefore critically to evaluate the optimal strategies for the management of post-operative recurrence in CD. Most, if not all, of the evidence available deals with …

The second European evidence-based Consensus on the diagnosis and management of Crohn's disease: Special situations