Rectal cancer refers to cancer located between the dentate line and the junction of the sigmoid colon and rectum. It is one of the most common malignant tumors in the gastrointestinal tract. The main manifestations are dull abdominal pain and abdominal discomfort; when rectal cancer progresses to the late stage, there will be obvious lower abdominal pain. As the disease progresses and the tumor grows to a certain extent, the patient will experience systemic symptoms such as anemia and weight loss. Its incidence rate ranks third among malignant tumors in the world. In 2011, the incidence rate in my country was about 23/100,000, and the mortality rate was about 11/100,000, and it has been increasing year by year. However, the early colorectal symptoms are not obvious, and most patients are already in the late stage when diagnosed. The 5-year survival rate of such patients is less than 10%. More than 90% of the cases are over 40 years old. The incidence rate of colorectal cancer in men and women is similar worldwide, with men slightly higher than women.