The incidence and death rates of colorectal cancer in China are on the rise. China’s cancer statistics report shows that the incidence rate and death rate of colorectal cancer in China rank third and fifth among all malignant tumors, with 376,000 new cases and 191,000 deaths. Among them, urban areas are much higher than rural areas, and the incidence rate of colon cancer has increased significantly. Most of the patients are in middle or late stage when they are diagnosed. The causes of colorectal cancer, like other cancers, have not been fully understood so far. The following factors may be related to the incidence of colorectal cancer. Genetic factors: It is estimated that genetic factors may play an important role in about 20% of colorectal cancer patients. 2.Dietary factors: It is generally believed that high animal protein, high fat and low fiber diet is the factor of high incidence of colorectal cancer. 3.Non cancerous diseases of colorectum: ulcerative colitis, colorectal polyps, colorectal adenoma, Crohn’s disease, schistosomiasis and so on. The incidence rate of hereditary colorectal cancer accounts for about 6% of the overall incidence rate of colorectal cancer, related family history: Lynch syndrome, familial adenomatous polyposis, etc. 4. Other factors: e.g. environmental factors, lack of molybdenum, long-term exposure to asbestos, poor lifestyle (sedentary, lack of physical activity, overweight, obesity, etc.) II. Census and screening (fecal examination, anal diagnosis, colonoscopy, etc.) Anorectal fingerprinting: more than 70% of Chinese patients with colorectal cancers have low rectal cancer, which is so close to the anus that it can be palpated through rectal fingerprinting. Ordinary colonoscopy: It is the easiest, safest and most effective way to detect intestinal tumors and precancerous lesions. However, after all, endoscopy is an invasive way of examination, with certain discomfort and complications, therefore, a lot of people are afraid of this kind of examination, resulting in some colorectal lesions and even tumors can not be diagnosed at an early stage, and the best time for treatment is delayed. Painless colonoscopy. The essence is to inject a fast-acting and precise anesthetic drug through vein before colonoscopy, so that the patient will fall asleep in a few seconds and wake up after completing the whole examination, and there will not be any discomfort and pain in the process of examination, so it is more and more popular among patients. What are the manifestations of colorectal cancer? Early colorectal cancer may have no obvious symptoms, but the following symptoms may appear when the disease develops to a certain extent: (1) Change of bowel habit (constipation or diarrhea, or both alternately). (2) Changes in the character of stool (thinning, bloody stool, mucus stool, etc.). (3) Abdominal pain, bloating or discomfort. (4) Abdominal mass. (5) Symptoms related to intestinal obstruction. (6) Systemic symptoms: such as anemia, emaciation, malaise, low fever and so on. Treatment of colorectal cancer: Early colorectal cancer treatment effect is very ideal, with 5-year survival rate of more than 90% after surgical treatment, while 5-year survival rate of advanced colorectal cancer is less than 50%. Therefore, early detection and timely treatment is an effective way to improve the cure rate of colorectal cancer. People with high-risk factors must have regular medical checkups; once symptoms such as change in bowel habit or blood in stool appear, they should consult the doctor in time. Once diagnosed with colorectal cancer, the only truly effective treatment is surgical resection of the tumor. For patients with progressive cancer, adjuvant treatments such as chemotherapy, targeted therapy and immunotherapy are also needed. Different surgical methods are used according to different parts of the tumor, such as right hemicolectomy, left hemicolectomy, sigmoidectomy, radical rectal cancer surgery (including anus-preserving and no-anus-preserving styles). Surgical methods can be divided into traditional open surgery and laparoscopic surgery. Laparoscopic surgery has the advantages of less trauma, less bleeding, faster recovery of intestinal function, shorter hospitalization time, etc. The effect of radical treatment and long-term survival rate are similar to that of traditional surgery. Prevention of colorectal cancer: Eat more yams, sweet potatoes, corn, fruits, fresh vegetables and other foods rich in carbohydrates and crude fibers, which have a short stay time in the intestinal tract and are conducive to the elimination of toxins in the intestinal tract. Try to eat less fried, smoked, high-fat and high-protein foods, and do not eat fruits, vegetables and foods that are likely to rot. The high-risk groups of colorectal cancer are: people over 30~40 years old, more common over 60 years old, people with digestive symptoms; people with a history of colorectal cancer; people with pre-cancerous lesions of colorectal cancer such as adenomas, ulcerative colitis, and schistosomiasis; people with a family history of cancer, familial history of polyposis, and hereditary colorectal disease; people with a history of pelvic radiotherapy; and people with a history of cholecystectomy or appendectomy. People with these high-risk factors should have regular medical checkups, annual fecal occult blood tests and anal fingerprinting, and colonoscopy when necessary. Active treatment of colorectal diseases such as ulcerative colitis and intestinal adenomas is also crucial. Postoperative dietary precautions: Colorectal cancer patients should choose the quality and quantity of diet reasonably after surgery. Postoperative recovery diet usually starts from drinking water, and gradually goes over to liquid diet and semi-liquid diet. When the condition recovers, it is advisable to choose high protein, high calorie, low fat and easy to digest food, and add or subtract supplements according to the character, frequency and quantity of stools, etc. It is forbidden to eat spicy and stimulating food, and it is better to have a light diet without greasy food. Rectal surgery patients will appear early intestinal dysfunction, the most common is diarrhea, followed by constipation, generally 3~6 months after surgery after significant relief, without special treatment. For those with frequent diarrhea, consider antidiarrheal drugs for symptomatic treatment.