Colorectal cancer is a preventable and treatable malignancy. Due to the effectiveness of preventive measures and health education, the incidence and mortality rate of colorectal cancer in the United States are in a declining stage, while the incidence and mortality rate of colorectal cancer in China are in a rapidly increasing stage. The symptoms of colorectal cancer (i.e. colorectal cancer) are insidious, and patients may not have obvious local symptoms in the early stage of the disease or even in the late stage of the disease, so that many patients are already in the middle or late stage when they are diagnosed, and the treatment effect is greatly reduced. Therefore, intestinal health screening is particularly important. There are various methods of intestinal health examination: 1.rectal anal finger examination: more than half of colorectal cancers occur in the rectum, and 80% of rectal cancers belong to low to medium level, which can be detected by rectal anal finger examination. 2.Fecal examination: fecal occult blood test can be used as a screening tool for colorectal cancer, which can provide clues for early diagnosis and is recommended to be examined once a year. 3.Colonoscopy: More than 70% of colorectal cancer occurs in rectum and sigmoid colon, and colonoscopy is the most effective means to detect early colorectal cancer. Colonoscopy not only can clearly observe the intestinal tract, but also can take suspicious lesions for pathological examination under direct vision, which is conducive to the detection and confirmation of early and micro colorectal cancer. Another major significance of colonoscopy is that it can detect and treat precancerous lesions such as intestinal polyps, especially adenomatous polyps, through minimally invasive endoscopy. Studies have found that most colorectal cancers originate from adenomatous carcinomas. If adenomas can be detected by colonoscopy and minimally invasive endoscopic treatment at the asymptomatic stage when adenomas are not cancerous or at the early stage of cancer, the chance of their transformation to cancer can be blocked. The American medical community suggests that asymptomatic individuals over the age of 50 should undergo their first bowel health screening. The “Asia-Pacific Colorectal Cancer Screening Consensus Statement” developed by the Asia Pacific Colorectal Cancer Working Group also states that colorectal cancer screening should be performed after the age of 50. The statement also points out that Chinese, Japanese and Koreans are more likely to develop colorectal cancer than people from other countries. Therefore, our experts suggest that the screening age for colorectal cancer should be earlier than 40 years old, especially for those who have a family history of colorectal cancer or intestinal polyps. For those who have normal colonoscopy, they can be examined again after 5-10 years; if polyps are found, they must be reexamined strictly according to medical advice after removal, until they are not found and can be reexamined after 2-3 years. At present, few people take the initiative to do colonoscopy health examination for two reasons: firstly, people lack knowledge about colorectal cancer, and secondly, people are difficult to accept or even afraid of such invasive examination method as colonoscopy. This kind of fear makes many patients delay the disease, resulting in many clinical cases of colorectal cancer not being diagnosed and treated at an early stage and missing the opportunity of treatment. At present, with the development of medical technology and the improvement of physicians’ operational proficiency, the discomfort of colonoscopy has been greatly reduced and the examination time has been greatly shortened, taking about a quarter of an hour to complete a colonoscopy. In addition, painless colonoscopy can also be performed under intravenous anesthesia. If you have recently experienced unexplained bloody stools, mucus stools, or changes in stool habits, please do not delay and go to the hospital for examination as soon as possible, regardless of your age.