Pain control following major spine surgery is difficult to achieve. Opiates are often necessary in high doses, and may be associated with significant side effects. Such side effects may include urinary retention, altered mental status, depressed respiratory drive, and constipation, and may lead to reduced nutritional intake in the postoperative period. Importantly, post-operative nutrition may impact the incidence of complications following spine surgery.1 Alvimopan is a peripheral-acting opiate antagonist designed to decrease the gastrointestinal complications of perioperative systemic opioid administration.