Alvimopan as a Rescue Treatment of Postoperative Ileus

This study aims to evaluate the cost effectiveness of Alvimopan as rescue therapy in patients undergoing colorectal or small bowel resection who develop POI, and its safety and effectiveness in reducing LOS and POI duration. Hypothesis: The investigators hypothesize that the use of alvimopan as rescue therapy in patients undergoing colorectal and small bowel resection surgery who develop POI can shorten their duration of POI and hospital length of stay. Objectives: To perform a prospective RCT to evaluate the effect of alvimopan as rescue therapy compared to standard of care in reducing the duration of post-operative ileus and post-operative LOS after colorectal and small bowel resection surgery. Protocol: This will be a prospective randomized control trial with a total of 58 patients, 29 in each group. Patients who undergo laparoscopic or open colorectal resection, small bowel resection, or ileostomy reversal with small bowel resection that subsequently develop postoperative ileus will be eligible for enrollment. If they meet inclusion/exclusion criteria, they will be randomized at the time of diagnosis of postoperative ileus to receive Alvimopan as rescue therapy or to receive conservative standard care. At the time of diagnosis of postoperative ileus and after enrollment and randomization, all patients will be returned to NPO status. Nasogastric tubes (NGT) may be placed for gastric decompression at the discretion of the surgical team if clinically indicated. In the event that an NGT is placed, medications will be given orally or via the NGT, which will be clamped for 30 minutes after administration. Patients will continue on standard ERAS pathways with the exception of reduction of diet. Antiemetics will be given as clinically indicated; however, no prokinetic or promotility agents will be given as scheduled dosages. Patients randomized to the study group will be given a maximum of 3 doses of Alvimopan 12mg orally, 12 hours apart. Alvimopan will be given from the time of diagnosis of postoperative ileus to the time of return of bowel function or the maximum 3 doses. Subsequent Alvimopan doses will be given if there is no return of bowel function or if symptoms of distension and/or nausea persist despite some return of bowel function. All patients will follow a standard ERAS pathway after surgery, with early feeding and ambulation, along with opioid minimizing measures as is our standard postoperative protocol. The patient and surgical team will be able to know which arm of the study the patient is in based on documentation in the medical record of the administration of Alvimopan. Standard discharge criteria will be applied to all patients, including: Passage of stool, Ability to tolerate solid food and to drink comfortably, Adequate oral analgesia, Patient's willingness to be discharged.