BACKGROUND: Postoperative ileus (POI) is a temporary delay of coordinated intestinal peristalsis following major abdominal surgery, leading to significant symptoms such as nausea, vomiting, abdominal pain, prolonged hospitalization, nosocomial complications, and physical deconditioning. The use of opioids for postoperative pain control further exacerbates the problem. Opioids bind to the mu receptors in the intestinal tract, leading to gut hypomotility. Alvimopan, an oral, peripherally acting mu-opioid receptor antagonist, was FDA approved in 2008 for use before and after bowel resection to help prevent and treat POI. There are no dedicated studies of alvimopan in patients with inflammatory bowel disease (IBD). Therefore, we conducted a study to investigate alvimopan's role in IBD patients who underwent either laparoscopic or open bowel resection. METHODS: A retrospective chart review was conducted at a 725-bed acute care teaching hospital in New York City between January 2012 and February 2017. Data collected included age, sex, type of IBD, length of stay, post-operative gastrointestinal symptoms (nausea, vomiting, constipation, abdominal distention, first flatus, first bowel movement, PO tolerance), and dose of alvimopan, were collected. The primary outcome was time to GI recovery. Secondary outcomes were: time to first flatus, time to first bowel movement, time to tolerating a liquid diet, time to tolerating solid food, and total length of stay. Descriptive statistics reports were created through a secure web-based application called REDCap (Research Electronic Data Capture), and the data were exported into Stata to run further analyses. Of note, approximately 50% of patients who underwent bowel surgery after March 2015 were placed on a “colon surgery pathway”, which is an order set dedicated to strategies that decrease length of stay and post-operative complications. Key features include early feeding, optimized analgesia regimen to allow patients to ambulate, encouraging use of incentive spirometry, and administration of alvimopan peri-procedurally. RESULTS: Of 247 patients, 121 received alvimopan (49.0%) and 126 (51.0%) did not. The male to female ratio was 51:49. The mean age of the control group was 44.4 ± 16.3 and that of the alvimopan group was 43.2 ± 16.4. Patients who received alvimopan had faster GI recovery, with a hazard ratio (HR) of 2.11 (P<0.001), shorter time to first flatus (HR 2.02, P<0.001), shorter time to first bowel movement (HR 1.93, P<0.001), shorter time to tolerating liquid diet (HR 2.48, P<0.001), and shorter time to tolerating solid food (HR 2.00, P<0.001). After controlling for type of bowel resected (large vs. small bowel), laparoscopic vs. open, age, and type of IBD (ulcerative colitis vs. Crohn's disease) using linear regression, patients who received alvimopan spent 2.59 fewer days in the hospital compared to the control group (P<0.01). CONCLUSION(S): The results of this study suggest that alvimopan is effective in accelerating the time to GI recovery. Data analysis of all primary and secondary outcomes revealed that alvimopan had a statistically significant benefit during the post-operative period of IBD patients undergoing bowel resection. Length of stay for IBD patients was significantly decreased with peri-operative use of alvimopan.