On the ward, patients will be prescribed acetaminophen 1 g every 6 hours. If additional analgesia is required, patients will take oxycodone 5-10 mg up to every 2 hours or iv morphine. Patients with contraindications to oxycodone will be prescribed oral hydromorphone 1-2 mg instead. This is the current standard of care at Toronto Western Hospital.

The TAP block will be performed after the induction, before the surgery, by an anesthesiologist with experience of at least 10 successful TAP blocks.Also patients will be prescribed acetaminophen 1 g every 6 hours. If additional analgesia is required, patients will take oxycodone 5-10 mg(oral hydromorphone 1-2 mg) up to every 2 hours or iv morphine.

Block needle will be inserted out-of-plane to the ultrasound beam, perpendicular to the skin surface, until the tip lies deep between the fascia of the transversus abdominis muscle and the internal oblique muscle. 30 ml of the study solution in each side will be injected at this location and should be observed to spread in an anterior-posterior direction between two muscles. Each patient will receive a total dose of 60 ml of 0.25% bupivacaine (150 mg) + 1:200,000 epinephrine.

Opioid consumption will be expressed in terms of milligrams doses of PO morphine. If other opioids are used, doses will be converted to the equivalent PO morphine dose using standard opioid dosage conversion tables.

Measured with a visual analogue scale (VAS, from 0 to 10), in the postoperative care unit, at rest and on movement (coughing).

Opioid consumption expressed as milligram doses of PO morphine in the postoperative care unit and at 48 hours.If other opioids are used, doses will be converted to the equivalent PO morphine dose using standard opioid dosage conversion tables