A prospective randomized trial will be performed. Patients undergoing laparoscopic Roux-en-Y gastric bypass will be randomized into 2 groups: patients undergoing laparoscopic-guided TAP block with 30 ml Bupivacaine 0.5%, as part of multimodal analgesia (Group 1), associated with postoperative intravenous analgesia (Metamizol 2g/8h and Acetaminophen 1g/8h), and patients receiving only postoperative intravenous analgesia (Metamizol 2g/8h and Acetaminophen 1g/8h) (Group 2).