Sigmoid colon cancer is a kind of colon cancer, and its site of incidence is located in the sigmoid colon part of the colon, which is a common site of colon cancer. In the early stage, there are often no special symptoms, but changes in bowel habits and stool characteristics are often the earliest symptoms, mostly manifested as increased frequency of bowel movements, diarrhea, constipation, blood, pus or mucus in stool. Sudden left lower abdominal cramps with abdominal distension, hyperactive bowel movement and cessation of defecation are the main manifestations of acute intestinal obstruction associated with cancer. The sigmoid colon is relatively free, and the mass is highly mobile. Usually, the mass can be found on the initial examination of the abdomen, and it is more fixed when the mass invades the lateral pelvic wall. As the disease progresses, the patient may develop anemia, wasting, weakness, and hypothermia. In the late stage of the disease, liver enlargement, jaundice, edema, ascites and enlarged supraclavicular lymph nodes may appear. Colon cancer mainly metastasizes through lymph, and sigmoid colon cancer often invades the bladder, uterus and ureter. Colon cancer is one of the tumors in the digestive system with a better prognosis. Colon cancer screening for high-risk groups and healthy eating habits can reduce the incidence and mortality rate of colon cancer.