For the initial mobilization of the sigmoid colon, the patient is rotated to the right. The sigmoid colon is grasped with an atraumatic forceps and retracted medially. The peritoneal attachments are then divided using the ultrasonic shears and blunt dissection (Figure 3). Care is taken to identify the ureter and avoid ureteral injury. The peritoneal attachment is divided up to the splenic flexure. This is facilitated by the first assistant or surgeon providing counter-traction of the colon. As the dissection nears the splenic flexure, it is best to stay underneath the omentum and develop a plan between the omentum and the splenic flexure (Figure 4). Dissection between the omentum and spleen can lead to splenic injury. The omentum is separated for a variable distance along the transverse colon depending on the amount of colon to be removed and the amount of mobility that will be necessary to complete a tension-free anastomosis. Mobilization of the splenic flexure and the transverse colon may be facilitated by a reverse Trendelenburg position. The proximal rectum is mobilized (Figure 5). In Figure 5, the orientation of the dissection is rotated so the head is to the reader's left and the foot to the right. The line of mesenteric incision is shown. The surgeon needs to know the anticipated position of the left and right ureter.