BackgroundVedolizumab is a biologic, which inhibits leukocyte adhesion in the gut and is used to treat ulcerative colitis (UC) and Crohn's disease (CD). Little is known of the surgical outcomes in patients treated with vedolizumab. We reviewed the postoperative complications in a cohort of pediatric UC and CD patients treated with vedolizumab. MethodsWe identified pediatric UC and CD patients treated with vedolizumab at our institution from 2014 to 2016. We compared postoperative outcomes in the vedolizumab exposed group to a cohort of vedolizumab naïve patients who required diverting ileostomy. ResultsOf the 31 patients who were treated with vedolizumab, 13 patients required surgery. Eight of 13 (62%) vedolizumab exposed patients had a postoperative complication, including mucocutaneous separation at the stoma (3), readmission for pain/dehydration (2), bowel obstruction at the ostomy, and intraoperative colonic perforation. In comparison, four of 16 (25%) vedolizumab naive patients had a postoperative complication, including readmission for ileus and for high stoma output with mucocutaneous separation. p=0.07. ConclusionsAt our institution, patients treated with vedolizumab prior to surgery have a high prevalence of postoperative complications, notably mucocutaneous separation of the stoma. A prospective, multicenter study is needed to determine if these observed complications are attributable to vedolizumab. Level of evidenceLevel III.