Mobilize the digestive viscera to expose the posterior abdominal wall.

1. Securely tie two loops of string (or electrical ties) separated by 5 cm around the lower rectum. Use a scalpel to cut the rectum between the two strings.
2. Use your fingers to mobilize the rectum, sigmoid colon and descending colon by ripping the peritoneum. Make certain that the branches of the inferior mesenteric artery and vein stay with the colon. Cut the inferior mesenteric artery leaving a 2 cm stump on the abdominal aorta. You may also need to cut the superior rectal artery and vein.
3. Mobilize the stomach, spleen, pancreas, small intestine, cecum and ascending colon by ripping any remaining peritoneum fixing the viscera to the posterior abdominal wall. You should now be able to displace the viscera towards the upper right quadrant of the peritoneal cavity. Make certain that you do not accidentally mobilize the kidneys, renal vessels, ureters or gonadal vessels with the digestive viscera.