 Background and treatment procedure: Liposomal bupivacaine is a multi vesicular formulation of bupivacaine that has been shown to provide up to 72 hours of analgesia compared to bupivacaine which provides up to 24 hours of analgesia post injection. These two medications have been compared using a infiltration or injection at the site of incision but have yet to be compared when used during a TAP block. A TAP block is an injection of local anesthetic under the covering of the transversus abdominis muscle layer. This layer is found using an ultrasound which is a beam of high frequency sound that allows one to visualize images in the body. Then using this ultrasound we can see our needle as it pierces the covering of the transversus abdominis muscle layer and watch as the local anesthetic is injected into this plane. This is done on both sides of the abdomen to provide analgesia to the skin, muscle, and fascial layers of the abdomen. 