In recent years, the incidence of colorectal cancer has gradually become younger, and nearly 10 patients between 20 and 30 years old have been admitted to our department in the past two years. This group is characterized by late stage of disease and easy recurrence and metastasis after surgery. The prognosis is not ideal. Therefore, we are more cautious in the outpatient clinic in the treatment of patients. For patients with blood in stool, heavy abdominal symptoms, change in bowel habits, long-term blood in stool and large amount of blood in stool, we will recommend colonoscopy. Avoid missed diagnosis and misdiagnosis. There is an increased incidence of colorectal disease in young people, and the cause is not yet clear. It may be related to poor dietary habits, excessive intake of red meat, poor living habits, prolonged late night, mental stress, addiction to smoking and alcohol, and family genetics. So once you feel uncomfortable, it is recommended to seek medical attention as soon as possible.