Effects of Vaping on Post-operative Recurrence of Crohn's Disease

This is a multicenter study with the aim of evaluate the effect of e-cigarette smoke (vaping) on Crohn's disease post-operative. Secondary objectives are : * To evaluate the effect of e-cigarette smoke on Crohn's disease postoperative recurrence compared to tobacco smoke. * To determine the effect of heat-not-burn tobacco products (ie. IQOS) on Crohn's disease postoperative recurrence compared to tobacco smoke. * To determine the effect of tobacco smoke on Crohn's disease postoperative recurrence compared to nonsmokers. * To account for the confounding effect of known risk factors of post- operative recurrence: biologic treatment for postoperative prophylaxis, penetrating complications, multiple intestinal resections. The subjects considered are adult patients (≥18 years) diagnosed with CD who underwent surgical resections of a tract of intestine accessible through endoscopy.