Colorectal cancer, also known as colorectal cancer, including colon cancer and rectal cancer, refers to cancer from the epithelium of the large intestine. As one of the most common malignant tumors in life, colorectal cancer ranks third in malignant tumors and fifth in lethal factors. China has a large population base and colorectal cancer is a high incidence disease. Its incidence rate and mortality rate are on the rise. According to statistics, the rising rate of the disease in China far exceeds the international level of 2%, approaching 5%, and the number of new cases is as high as 400000 every year. What is more interesting is that this cancer, which used to belong to the elderly, has quietly targeted young people in their 30s. The overall average age of onset has tended to developed countries, and 85% of patients are diagnosed as advanced. High risk factors of colorectal cancer 1. Dietary structure Dietary factors play an important role in the development of colorectal cancer. A diet with high animal protein, high fat and low fiber is the decisive risk factor, especially the food after frying, smoking and baking. On the contrary, fresh vegetables and fruits can provide crude fiber in the body and supplement vitamins and trace elements, which is of great benefit to the intestine, promote intestinal peristalsis and reduce the deposition of intestinal garbage, Reduce the incidence of colorectal cancer. The high content of hematite in red meat has been proved to promote the occurrence of colorectal cancer by stimulating the formation of endogenous carcinogen nitroso compounds. The fat content of processed meat is higher than that of red meat. Through the synthesis of bile acids, bile acids decompose fat to form a large number of carcinogens, and saturated fatty acids are also one of the causes of cancer. 2. Smoking Smoking is one of the important factors inducing colorectal cancer. Every 10 cigarettes / day increase in smoking can increase the risk of colorectal cancer by 7.8%. 3. Obesity The prevalence rate of obese people is about 1.5-2 times that of ordinary people. This is because obese people have high insulin levels. The increase of insulin levels will promote cell growth and inhibit apoptosis, which is related to the increased risk of colorectal cancer. 4. Excessive drinking The main substance of alcohol is ethanol, which will produce toxic metabolite acetaldehyde after oxidation, which can cause cancer to colon cells. Alcohol can also be used as a carcinogenic solvent to promote carcinogens into the mouth, esophagus and gastrointestinal tract, increasing the risk of colorectal cancer. 5. Genetic factors It can be divided into hereditary and non hereditary. Typical examples of the former are familial polyposis of colon syndrome and familial hereditary non polyposis of colon cancer. The latter is mainly caused by environmental factors. In hereditary colorectal cancer, the influence of heredity is greater. The risk of familial genetic cancer is closely related to family history, and its risk degree is related to the number of relatives with this cancer, whether they are first-degree relatives and age of onset. 6. Inflammatory bowel disease The incidence rate of ulcerative colitis and other inflammatory bowel disease increases with the extension of the course and the enlargement of the lesion area. 7. Other factors Cholecystolithiasis, diabetes, sedentary and lack of exercise are also associated with colorectal cancer. High risk groups of colorectal cancer High risk groups should be screened in advance. The starting age of screening is recommended to be before the age of 40, and enteroscopy is recommended for screening. Familial polyposis and other genetic diseases should be intervened in adolescence. 1. People aged 30 to 40 and above with gastrointestinal symptoms (especially those with bloody stool, stool frequency, mucus stool and abdominal pain) 2. High incidence areas of colorectal cancer are mainly middle-aged and elderly people in large cities 3. Those with precancerous lesions, such as colorectal adenoma, ulcerative colitis and schistosomiasis 4. Family history of colorectal cancer, familial polyp and hereditary colonic disease 5. History of pelvic radiotherapy 6. A history of cholecystectomy or appendectomy These symptoms need to be vigilant against colorectal cancer 1. The change of defecation habit, constipation and diarrhea alternately, accompanied by the feeling of anal distension; Change and thinning of stool shape; Bloody stool or black stool. 2. Fever, fatigue, unexplained anemia and sudden weight loss. 3. Abdominal mass. 4. Enteroscopy revealed multiple polyps. Most gastrointestinal tumors have no typical symptoms or only atypical symptoms in the early stage. More than 90% of colorectal cancer will be misdiagnosed as hemorrhoids in the early stage and miss the best treatment period. The main reason is that the clinical manifestations of colorectal cancer and hemorrhoids have many similarities, so what is the difference between colorectal cancer and hemorrhoids? 1. In terms of age, hemorrhoids can occur in people of any age, while patients with colorectal cancer are mainly concentrated in the middle-aged and elderly. 2. The blood in the stool of patients with hemorrhoids is caused by scratching the affected area during defecation. Most of the blood drips down after defecation, so it will not mix with the stool, only stay on the surface of the stool, and there will be no mucus; The stool of patients with colorectal cancer is often mixed with blood, mucus and pus, and the color is darker than that of hemorrhoids. Screening methods for cancer 1. Digital rectal examination More than 50% of colorectal cancer occurs in the rectum, and 70% of rectal cancer patients are mostly low rectal cancer. About 80% of rectal cancer can be found through digital rectal examination. It is a method to find early rectal cancer, but there is nothing to do with the large intestine outside the rectum. 2. Endoscopy Including anoscope, fibrocolonoscopy, sigmoidoscopy, etc. anoscope can see 10 cm, sigmoidoscopy can see 25 cm, fibroscope can see the general shape of all colon, and biopsy can be taken for tissue cytology examination. It is a powerful means for early detection of colorectal cancer. It is suggested that people over 40 years old should have an enteroscopy if they have symptoms or not. 3. Fecal examination Fecal occult blood test can be carried out every year or every 2 years to screen colorectal cancer. If it is positive, enteroscopy should be carried out. However, it should be noted that red meat, raw horseradish, radish, broccoli, etc. cannot be eaten in the first three days of occult blood test, and false positive reaction will occur. 4. X-ray examination X-ray examination, including barium enema and abdominal plain film, is very valuable for early detection of colorectal cancer. Prevention and health care of intestinal cancer 1. Healthy diet Eat more vegetables and fruits containing more cellulose, increase the intake of cellulose and vitamins, and avoid high-fat and high protein diet. Various powerful antioxidants in cruciferous vegetables can help us eliminate pollution and speed up our detoxification process. Eating cruciferous vegetables three times a week can reduce the risk of colorectal cancer by 60%. 2. Movement The study found that people who are active at work have a 40-50% lower risk of colorectal cancer than those who work in the office. It is recommended that you have 30 minutes to exercise every day. 3. Coffee Two cups of decaffeinated coffee a day can reduce the incidence of colorectal cancer by 52% and lose weight. 4. Bask in the sun Vitamin D can prevent the incidence of rectal cancer, but vitamin D in the skin needs ultraviolet radiation to play an anti-cancer role, so it needs to be exposed to the sun for 10-15 minutes every day. 5. Quit smoking and drink Avoid the long-term toxicity and irritation of tobacco and alcohol to the digestive tract. 6. Pay attention to early screening Colorectal cancer is a long evolution process influenced by multiple stages and factors. The study found that the canceration process of nearly 90% of colorectal cancer takes 5-10 years. Through screening and general survey, colonoscopy for high-risk groups can early diagnose and treat the precancerous lesions of colorectal cancer. It is suggested to pay attention to colorectal cancer screening from the age of 40. (outlook new era)