The investigators' goal in this planned prospective, randomized, patient blinded study is to compare our standard of care as the control group to an experimental group in which patients receive preemptive IV acetaminophen dosing that is continued every 6 hours for a total of 8 doses in patients who have undergone major gynecologic surgery. The outcomes analyzed will include amount of rescue opioids required, time to return of bowel function, length of hospital stay, cost effectiveness, and patient satisfaction. The hypothesis is that the addition of IV acetaminophen will decrease the need for opioid rescue and thereby decrease the incidence of associated gastrointestinal side effects including nausea, vomiting, bloating, and constipation. The hope is that it will affect the final outcome of quicker return of bowel function, increased patient satisfaction, shortened hospital stay and prove to be an overall more cost effective postoperative pain management approach.