Colorectal cancer ranks fourth among malignant tumors in China and seriously threatens people’s lives. In developed countries, 90% of bowel cancer patients are over 50 years old, while in China, the high incidence age is 10 years earlier. The high incidence of colorectal cancer is related to the level of economic development, and early screening can reduce the risk of cancer. The high incidence of colorectal cancer is related to the level of economic development From epidemiological studies, the high incidence of colorectal cancer is mainly concentrated in the more developed countries and regions with higher economic level. From a worldwide perspective, regions like the United States, Europe and China are generally high in incidence; while for the domestic situation, it is mainly concentrated in Guangdong, Shanghai, Beijing and other places. Prof. S.D. Liu told the editors of Family Doctor Online that from the perspective of the age of onset of colorectal cancer, the incidence in China is not quite the same as that in foreign countries. This may be related to China’s special diet and work pressure, excess nutrition or irregular diet, etc., which induces colorectal cancer. Colonoscopy can screen bowel cancer and remove early lesions to reduce the risk of cancer Statistics show that as of 2012, there are about 1.36 million new cases of colorectal cancer and about 690,000 deaths worldwide, with men slightly more than women. From the perspective of China’s incidence, as of 2010, there were more than 270,000 new cases of colorectal cancer and 130,000 deaths in China. The incidence of colorectal cancer is very serious. It is understood that colonoscopy is the main means to screen and confirm the diagnosis of colorectal cancer nowadays, and the cost of the examination in tertiary hospitals is about 300 RMB. Although colonoscopy is inexpensive and necessary, many people still do not recognize it, and generally think that it is troublesome and painful to do colonoscopy. Prof. S.D. Liu said, “Although it is true that colonoscopy can cause some discomfort to patients, the benefits of colonoscopy to the public are enormous. During the examination, polyps with cancer risk can be directly removed to avoid cancer; for adenomas that have produced precancerous lesions, they can be directly removed; for early colorectal cancer, radical treatment can greatly improve the quality of life of patients and enhance the treatment effect.” People over 40 years old need to have a colonoscopy, and if there is no problem, then they can have another one after 3 years. This is because it takes 7-15 years for an adenoma to develop into cancer, and if it is detected and removed during this period, it can be prevented from developing into bowel cancer. In addition, if there are some obvious changes in bowel movement, it is time to be alert. Firstly, the change of stool regularity; secondly, the change of stool shape; in addition, the appearance of abnormal things in stool, such as blood in stool. Especially, blood in stool caused by early bowel cancer can be easily misdiagnosed as bleeding from hemorrhoids. Once you encounter these three cases, it is better to go to the hospital for colonoscopy, so that early diagnosis and treatment can be made.