The serosa along the mesenteric border of the upper segment should be cleared of fat for at least 1 cm proximal to the Pace-Potts clamps (Figure 5). Likewise, the margins and especially the posterior wall of the lower segment must be cleared of fat adjacent to the Pace-Potts clamp (Figure 5). Careful dissection with repeated application of small clamps may be necessary to accomplish a clean serosal boundary of 1 cm adjacent to the clamp in preparation for a safe anastomosis. Following this, the two ends of the clamps are approximated and then manipulated so that a posterior serosal layer of 000 silk can be placed easily (Figure 6). The ends of these sutures are cut, except those at either angle, which are retained for traction. As a preliminary to removing the clamp, the field is walled off with gauze, and an enterostomy clamp is gently applied to the upper segment to prevent gross soiling (Figure 6). The crushed contents of the clamps may be excised. The lower clamp is then removed, and the crushed margin of bowel is excised and opened (Figure 7). Suction is instituted to avoid any gross contamination of the field. Fine silk sutures may be inserted for traction in the midportion of the lower opening and at either angle. These traction sutures tend to facilitate the anastomosis (see Plate 86, Figures 16 & 17). The posterior mucosal layer is approximated with several Babcock forceps, and the mucosa is approximated with interrupted 000 silk sutures. The anterior mucosal surface is closed with interrupted 000 silk sutures of the Connell type, with the knot on the outside. The mucosa may be closed with a continuous 000 synthetic absorbable suture (Figure 8) rather than interrupted silk sutures. Following this, the anterior serosal layer is carefully placed, using interrupted Halsted sutures of fine 000 silk (Figure 9). The peritoneum is anchored adjacent to the suture line. The patency of the anastomosis, as well as the lack of tension on the suture line, should be tested. The peritoneal floor is closed with interrupted absorbable sutures (Figure 10). The raw surfaces are covered by approximating the mesenteric margin of the sigmoid to the right peritoneal margin (Figure 10). The sigmoid is loosely attached to the left pelvic wall by anchoring the fat pads, not bowel wall, to the left peritoneal margin to prevent subsequent tension on the anastomosis as well as to cover the raw surfaces. A transverse colostomy or diverting loop ileostomy (Plate 58) should be considered if there is any suspicion regarding the technical perfection of the anastomosis. A drain may be inserted into the left side of the pelvis and brought out at the lower angle of the wound. Some operators prefer to have a rectal tube in place, which can be guided up beyond the anastomosis to assist in decompressing the bowel during the early postoperative period. The rectal tube is anchored in position by a silk suture placed at the anal margin. Some prefer to use a surgical stapling instrument for the anastomosis. See Plates 81 and 82.