Patients undergoing major abdominal surgery are at highest risk for developing postoperative ileus (POI), occurring in nearly all cases. Signs and symptoms of POI may include abdominal distention and bloating, persistent abdominal pain; nausea and/or vomiting; delayed passage or inability to pass flatus or stool; and inability to tolerate a solid diet. This study will test the ability of alvimopan 6 mg or 12 mg given 2 hours before the scheduled start of surgery to hasten the recovery of GI function in patients undergoing major abdominal surgery (bowel resection or abdominal hysterectomy).

Postoperative ileus (POI) is a temporary slowing down or stopping of bowel function and a slowing down of movement of contents of the intestines. This functional impairment persists for a variable duration following surgery, usually resolving within 1 day in the small intestine, 1 to 3 days in the stomach and 3 to 5 days in the colon. When POI persists for more than 5 days, it is generally considered severe, sometimes referred to as complicated or prolonged POI, and increases the risk for related morbidity. No drug therapy has been shown to consistently shorten the duration of POI. This study is designed to demonstrate that alvimopan, a novel, peripherally acting mu opioid receptor antagonist, accelerates the recovery of GI function in patients undergoing bowel resection or hysterectomy.

Inclusion Criteria:

• Subject is scheduled for a partial small/large bowel resection with primary anastomosis or total abdominal hysterectomy (simple or radical) via laparotomy
• Subject is scheduled to receive primary postoperative pain management with intravenous (i.v.) patient-controlled analgesia (PCA) opioids

Exclusion Criteria:

• Subject is scheduled for a total colectomy, colostomy, ileostomy
• Subject has complete bowel obstruction
• Subject has recently been on an acute course (1-10 days) of opioid analgesics and has not been off all opioids for at least 1 week prior to surgery Subject has been on chronic (>10 days) opioid analgesics and has not been off all opioids for at least 2 weeks prior to surgery.