Polyp is actually divided into tumorigenic and non-tumorigenic. Tumorigenic polyp mostly refers to adenoma, especially familial adenomatous polyposis, if one person in the family is diagnosed, other members should undergo relevant examination and early treatment to prevent cancer. However, even adenomas usually take 5 to 20 years to develop into cancer, and the chance of cancer is related to the size, number, pathological type and location of adenomas, as well as the age and gender of the patient. Non-neoplastic polyps refer to inflammatory polyps and hyperplastic polyps, which are basically not cancerous, but should be removed as soon as possible. Etiology of colorectal cancer: The development of colorectal cancer is related to many factors, such as dietary habits, genetics and inflammation of the colon, etc. 1, dietary factors: such as high fat and low fiber diet; animal protein, high content of nitrosamines and their derivatives in food; intake of alcohol; fried food; vitamin A, C, E and trace element selenium deficiency, etc. Dietary factors are considered to be extremely important in the development of colorectal cancer. In the United States, this is also confirmed by the declining trend of colorectal cancer incidence due to the advocacy of dietary changes since the 1950s. In contrast, in China, with the increasing improvement of people’s living standards, the dietary habits of Chinese people have also undergone great changes, with high-fat, high-protein and high-calorie foods increasing in the menu. This is also the reason for the increasing incidence of colorectal cancer in China. 2.Some benign lesions of the colon: such as chronic ulcerative colitis, colonic adenoma, familial colonic adenomatosis, schistosomiasis, colonic polyps, etc. The risk of colon cancer is several times higher in people who have had chronic ulcerative colitis for more than 10 years than in the general population, because repeated inflammation in the intestine is a chronic stimulus to the intestinal mucosal cells, and this stimulus over time can lead to uncontrolled growth of mucosal cells and malignant changes. The relative risk of colorectal cancer is 22 times higher than that of patients without polyps, because although polyps themselves are benign, they may become malignant. Genetic factors: It is estimated that genetic factors may play an important role in about 20% of colorectal cancer patients, such as familial adenomatous polyposis, hereditary non-polyposis colorectal cancer is the most common hereditary colorectal cancer. Studies have found that the risk of colorectal cancer in children of colorectal cancer patients is 2-4 times higher than that of the general population, and about 10%-15% of colorectal cancer occurs in people with a history of colorectal cancer in first-degree relatives. 4.Occupational factors and health habits: lack of physical activity can increase the risk of colon cancer. However, it is generally not considered that colorectal cancer is an occupational disease. Symptoms of colorectal cancer: 1. Blood in stool: It is the earliest and most common manifestation of colorectal cancer. In mild cases, it only shows a small amount of bleeding occasionally, and a small amount of bleeding can only be known after laboratory test. In severe cases, it can show mucus-blood stool, mucus-pus-blood stool or fresh blood stool, which is often misdiagnosed as dysentery or hemorrhoid bleeding and misses the time to confirm the diagnosis. Due to the different locations of the cancer, the bleeding volume and nature vary, and long-term bleeding may produce secondary anemia. 2. Abdominal pain: Some patients have persistent vague pain with inaccurate localization as the first or prominent symptom, while some patients only have abdominal discomfort or bloating. When colorectal cancer combined with erosion, obstruction or secondary infection, due to increased peristalsis and spasm of the corresponding intestinal segment, obvious abdominal colic may appear. Some patients show typical incomplete intestinal obstructive abdominal pain, i.e. the pain is paroxysmal colic, which lasts for several minutes, with self-conscious gas running through the pain, followed by exhaust, and then the pain suddenly disappears, when such symptoms appear in the elderly, colorectal cancer should be considered first. 3. Change in bowel habits: The change in the number of bowel movements or stool characteristics, for example, the original stool was once a day, but recently for unknown reasons it is 3 to 4 times a day, or the alternation of diarrhea and constipation, as well as the change in the shape of stool, which was soft and formed, but recently it is suddenly like water, and there seems to be blood or pus in it, remind that there may be problems in the intestinal tract, and you should go to the hospital for You should go to the hospital for a medical examination. (It should be noted that these symptoms are also common in other diseases, so a thorough physical examination should be performed if you have these symptoms). Some people also have a feeling of urgency, especially in young people. If there is no other reason (including travel, change of living environment and taking hyoscine, etc.) and constipation and diarrhea and other intestinal disorders often occur, and regular treatment is still ineffective for more than two weeks, it should be noted that it may be an early sign of colorectal cancer. 4.Anemia: male patients, especially those who have no other causes of blood loss or intestinal parasitic disease, should think of the possibility of stomach or colon cancer if they find progressive iron deficiency anemia.