The incidence of colorectal cancer has been increasing gradually in recent years, and there is a trend of youthfulness, which should attract our attention. Early detection and early treatment is the key to treat colorectal cancer, but due to the lack of typical clinical manifestations of colorectal cancer, patients often waste a lot of precious time and lose the opportunity to be cured from the time they have symptoms to the time they seek medical consultation. Early symptoms of colorectal cancer include: 1. change in stool habit (such as increase in the number of stools or diarrhea, constipation); 2. blood in stool (easily confused with hemorrhoids) or black; 3. deformation and thinning of stool; 4. urgency and heaviness (wanting to relieve after stooling); 5. intermittent abdominal cramps; 6. unexplained anemia, weight loss, mental discomfort and loss of appetite; 7. people with family history of colon and rectal cancer and other systems People with family history of colon and rectal cancer and other systemic cancers should pay more attention to the above symptoms.