In recent years, the incidence of colorectal cancer in China has been on the rise year by year, and the incidence rate ranks the 3rd among all tumors. The incidence rate of colorectal cancer in Guangdong is increasing by 4.2% per year, which exceeds the average growth rate of 3.9% in China and is more than twice of the world average growth rate (2%), and the incidence is gradually becoming younger. Observe defecation from three aspects 1, defecation feeling feces is the residue left by the digestion and absorption of food, enter the rectum through intestinal peristalsis. Pressure receptors in the rectum cause the desire to defecate, manifested as lower abdominal distension, anal swelling. This feeling disappears after the feces is expelled from the body. 2.Frequency of defecation The number of bowel movements per day is 1 to 2 times for normal adults, and 1 time every other day for a few people. Defecation less than 2 times a week should be regarded as constipation. Compared with the original bowel habits, you should be careful when you suddenly have too frequent bowel movements or longer intervals recently. 3. Nature of stool Mainly refers to the dryness and thinness of the stool. Usually formed soft stool, occasionally dry or thin stool is also normal, often related to dietary activities and mental factors. Unexplained change of stool is an alarm. Change of stool habit without obvious cause should also be regarded as an alarm for colorectal cancer. If there is an increase in the number of bowel movements without any cause, whether dry or loose, and if it is accompanied by incomplete defecation, it means that the pelvic floor and rectal nerve muscles are stimulated. At this time, if it is accompanied by blood or mucus in the stool, you should go to the hospital in time, and through anal examination or colonoscopy, you can exclude colorectal tumor disease, do not treat it as hemorrhoid attack and delay treatment. The literature reports that about 30%~80% of rectal cancer patients are misdiagnosed as internal hemorrhoids or dysentery before diagnosis. Change in stool habit is an early sign of colorectal cancer, and the 5-year survival rate of patients with colorectal cancer detected early and treated timely is over 90%; the survival rate of patients with late stage surgery is only 30%. Surgery is the only way to cure colorectal cancer, early stage colorectal cancer should be treated by radical surgery in time, and postoperative treatment with TCM can have a high cure rate; patients with middle and late stage colorectal cancer can also prolong their survival by combining radiotherapy and TCM anti-tumor treatment after having the opportunity to remove the primary lesion through surgery. In addition, we should pay attention to the following points in the prevention of colorectal cancer: we should try to avoid “three high and one low” foods in the diet, i.e. high fat, high protein, high calorie and low fiber foods, and we should eat a varied and extensive diet, not a partial diet. Moldy peanuts, sauerkraut, salted fish, salami and other pickled products, smoked products should not be excessively eaten; develop good habits, do not smoke, do not abuse alcohol.