Colorectal cancer, including rectal cancer and colon cancer, is one of the common malignant tumors. In the past 20 years, the incidence rate and death rate of colorectal cancer have gradually increased in China and the world. The incidence rate of colorectal cancer is 15.7/100,000 people, which is the fourth to sixth among malignant tumors in China, and the incidence rate is higher in economically developed areas, higher in urban than rural areas, and higher in large cities than in medium and small cities. The highest incidence rate is between 41-51 years old, which is a critical period of career, life and work pressure, and is most likely to have problems if we do not pay attention to our health care. The survival rate of early-stage colorectal cancer is over 90% in 5 years after surgery; the survival rate of late-stage cancer is less than 10% even after various comprehensive treatments. Therefore, middle-aged people over 40 should be alert to the invasion of colorectal cancer. For patients over 40 years old, if they have the following symptoms, they should pay attention to them: a. Change of stool habit without any special cause, persistent diarrhea or constipation. (2) No history of dysentery, enteritis, hemorrhoids, fistula, etc., but frequent stools, stools with pus and blood, mucus, blood stools. 3.Recent persistent abdominal pain, flatulence, abdominal discomfort, after general treatment is ineffective. 4. Those with gradually increasing symptoms of intestinal obstruction. V. Unexplained anemia, wasting or weight loss. Abdominal masses, especially in the left or right lower abdomen. If black or tar-like stool, positive occult blood test, red blood cells or white blood cells appear on microscopic examination, further examination should be conducted. In addition, because the early symptoms of colorectal cancer are not typical, most patients are already in the middle and late stages when they are diagnosed clearly and miss the best opportunity for treatment. Therefore, early detection and early treatment is the key to cure colorectal cancer. Therefore, once there are abnormal body reactions and uncomfortable symptoms, you should go to hospital in time to avoid delaying the disease.