["Anti-tumor necrosis factor (anti-TNF) therapy effects on postoperative complications in Crohn's disease (CD) patients are unclear. We examined a retrospective cohort to clarify this relationship.", 'CD patients followed at a referral center between July 2004 and May 2011 who underwent abdominal surgery were identified. Postoperative complications (major infection, intra-abdominal abscess, peritonitis, anastomotic leak, wound infection, dehiscence, fistula, thrombotic, and death) were compared in patients exposed and unexposed to anti-TNF ≤8 weeks preoperatively. Demographics, surgical history, comorbidities, corticosteroid (CS) and immunomodulator use, Montreal classification, operative details, and preoperative nutritional status were assessed. Multivariate analysis measured the independent effect of preoperative anti-TNF on postoperative complications.', 'Overall, 325 abdominal surgeries were performed; 150 (46%) with anti-TNF ≤8 weeks before surgery. The anti-TNF group developed overall infectious (36% vs. 25%, P=0.05) and a trend toward surgical site complications (36% vs. 25%, P=0.10) more frequently. Major postoperative and intra-abdominal septic complications did not differ between groups. Multivariable analysis showed that preoperative anti-TNF was an independent predictor of overall infectious (odds ratio (OR) 2.43; 95% confidence interval (CI) 1.18-5.03) and surgical site (OR 1.96; 95% CI 1.02-3.77) complications.'] Is anti-tumor necrosis factor therapy associated with infections after abdominal surgery in Crohn 's disease patients?