IV acetaminophen, which has been used successfully in Europe, was recently approved by the Federal Drug Administration (FDA) for use in the US. However, no data exist regarding the use of IV acetaminophen in bariatric surgery patients, nor are there any data assessing its cost effectiveness. Therefore, our study will investigate the economic impact of administering IV acetaminophen to bariatric surgery patients, as well as its effect on clinical outcomes such as patients' post-operative length of stay, self-reported pain, readmissions, emergency room (ER) visits and complications.