Despite the availability of biological drugs and the widespread and earlier use of immunosuppressants, intestinal resection remains necessary in almost half of the patients with Crohn's disease. The development of new mucosal lesions in previously unaffected intestinal segments (a phenomenon known as post-operative recurrence, POR) occur within the first year in up to 80% if no preventive measure is started soon after resectional surgery, leading to clinical manifestations (clinical recurrence) and even needing new intestinal resection (surgical recurrence) in some patients. That is the reason why endoscopic monitoring has been recommended within 6 to 12 months after surgery. Active smoking is the only indisputable risk factor for early POR development. Among several evaluated drugs, only thiopurine and anti-tumor necrosis factor therapy seem to be effective and feasible in the long-term both for preventing or even treating recurrent lesions, at least in a proportion of patients. However, to date, it is not clear which patients should start with one or another drug right after surgery. It is also not well established how and how often POR should be assessed in patients with a normal ileocolonoscopy within the first 12 months.
Keywords: Crohn’s disease; anti-TNF; calprotectin; ileocolonoscopy; recurrence; thiopurines.