Sigmoid resection with end-to-end colorectal anastomosis: After sigmoid resection, a purse-string suture is placed in the descending colon, and a circular anastomotic staple anvil is placed in the intestinal canal to tighten and tie the purse-string suture. After adequate dilation, the anastomosis body is inserted through the anus and slowly advanced, and the central rod is threaded out by rotating the adjusting screw, and the distal rectum is tightened and knotted on the central rod. The pre-set nail anvil in the colon is connected to the nail holder, and the tail nut is rotated to bring the anastomosis body close to the nail anvil, compressing the colon and rectum and completing the anastomosis by firing. After exiting the anastomosis, check the integrity of the upper and lower cut edges (see figure). Intraoperative enteroscopy can be prepared to observe whether there is active bleeding from the anastomosis, and if there is bleeding, it can be stopped by penetrating sutures. In order to avoid anastomotic leak in the application of the anastomosis requires attention: special attention should be paid to protect the blood flow of the proximal and distal intestinal canal; the proximal colon should retain the bowed margin vessels with pulsatile beating of the marginal vessels; the freeing of the intestinal wall at the ruffled end should not exceed 2.0 cm; the anastomotic staple should be routinely and carefully checked for completeness before anastomosis; the ruffled suture should be complete; the anastomotic end should be clamped with surrounding tissues, the freeing length of the intestinal canal is insufficient for the anastomotic site with The anastomosis should be carefully checked before the anastomosis to make sure that there is no surrounding tissue at the anastomosis site such as fat pendulous or the surrounding tissue is mistakenly clamped into the anastomosis end, and the two ends of the intestinal wall cannot be completely aligned. Avoid overgrown and outgrown tissues at the stump of the ruffle embedded in the anastomotic circle. The length of the intestinal canal removed by the anastomosis should be fully considered to prevent excessive anastomotic tension after the anastomosis; choose the appropriate type of anastomosis, and select the appropriate anastomosis according to the diameter of the anastomosed intestinal canal during the anastomosis.