The main treatment for stage III rectal cancer is post-synchronous chemotherapy, and if it can be reduced to a lower stage, radical surgery can be done to remove it, and then with post-operative adjuvant chemotherapy, the 5-year survival rate of stage III rectal cancer is about 50%, that is, about 50% of patients can live beyond 5 years. Early detection of rectal cancer is mainly based on timely detection of symptoms of rectal cancer such as blood in stool, abdominal pain, wasting and other symptoms, and timely anorectal examination and, if necessary, intestinal microscopy to obtain pathological tissue to find cancer cells.