Colorectal cancer in China for the first four to six common tumor. Domestic colorectal cancer incidence around the age of 45 years old, Compared to the United States early 15. My young cancer patients with colorectal cancer accounted for 23.7 percent. Colorectal cancer incidence and dietary factors have an important relationship, high-fat, &127; low fiber is the major risk factors for colorectal cancer.to increase anaerobic bacteria in the stool; cellulose in the absence of food, feces decreased, increased concentrations of carcinogens in the bowel caused cancer. Census methods have the following categories: A digital rectal examination is the main method, because colorectal cancer in 70% ~ 75% in the rectum and B intestine. In rectal cancer 75% can be found through the mass of digital rectal examination. 40-year-old above the crowd, to check once a year, especially in hematochezia, they frequency, stool mucus in bowel habits and such as abnormal, rectal examination should be done. Digital rectal examination understand from the general anal 8 cm within the scope of diseases, &127; such as increased abdominal pressure, and so do the breath moves may be found in higher positions. Second, fecal occult blood test is user-friendly and low-cost, 50-year-old crowd in each of the above inspections, can be used as a large-scale survey of colorectal cancer screening methods. If positive, then further to do fiber colonoscopy. Fecal occult blood test can be detected gastric ulcer, gastric cancer, colorectal polyps, and other digestive tract disorders, especially colorectal adenomas cancer rate can reach 10% to 20%. Third, sigmoid conditional examination from the age of 50 began three years in a row, the annual inspections. If negative, every four years since inspections. Where hematochezia or stool habits change, as no abnormal digital rectal examination Discoverer, should be routinely conducted sigmoid colon examination. About 75% to 80% of the rectum, sigmoid colon cancer can be diagnosed by sigmoid microscope. Such inspection and simple operation, in the lesions observed under direct vision, while at the same time collecting tissue samples from living, but also through Fulguration removed adenomas, and other pre-cancerous lesions. In short, we control the cancer patients in primary prevention, we can reduce the incidence of cancer; control in the secondary prevention can reduce the cancer patient's death.