Facing the rapidly increasing incidence rate, the diagnosis rate of early stage colon cancer in China has always hovered at 5%-10%, and more than 80% of patients are already in the middle or late stage when diagnosed, missing the best treatment period. In fact, if colorectal cancer can be detected and treated early, the 5-year survival rate after surgery can be over 80%. Therefore, it is very important to carry out early detection and treatment of colorectal cancer. Universal screening refers to one or more tests to confirm whether asymptomatic people have colon/rectal cancer or precancerous lesions. Primary screening refers to the examination of people with previous history of colon/rectal cancer or those who are at high risk. Further and more frequent screening is recommended for these individuals because of their high risk of developing cancer. There is another easy but very effective method that is often overlooked by doctors and patients, and that is the anal exam. Anoscopy is when the doctor sticks a finger into the patient’s anus for examination. The main reason why the misdiagnosis rate of rectal cancer is so high is the lack of attention to anal examination. On one hand, patients feel embarrassed to have this examination, and on the other hand, doctors neglect this simplest examination because of relying on advanced equipment. According to statistics, 60%-70% of the patients with colon/rectal cancer are rectal cancer, while 60%-70% of the patients with rectal cancer are low to medium rectal cancer. In other words, it is possible that nearly half of the colorectal cancer patients can be detected early through anal examination.