Colorectal cancer is a common malignancy in clinical practice. 10-20% of descending colon cancer, sigmoid colon cancer and rectal cancer are diagnosed with acute intestinal obstruction, which is often a closed-collar obstruction, prone to intestinal ischemia, necrosis and perforation, and due to the presence of a large number of bacteria in the intestinal cavity, the intestinal wall edema and intestinal canal dilatation are prone to serious infection. Factors such as poor blood flow in the left hemicolectomy, presence of large amount of feces in the intestinal cavity, and bacterial migration infection after intestinal wall edema after obstruction; most surgeons believe that intestinal fistula is prone to occur after one-stage resection and anastomosis, and the surgical risk is high, and they mostly adopt one-stage resection of tumor, colostomy, and two-stage anastomosis, and this choice of surgical procedure increases the pain and economic burden of patients, and also reduces the long-term survival rate of patients. We have achieved good results in dozens of patients with left hemi-intestinal obstruction by appendectomy, intraoperative colonic irrigation via the appendiceal stump, one-stage resection and colonic anastomosis to avoid colostomy.