It is also necessary to do colonoscopy for the elderly without any discomfort, especially for patients with family history of familial adenomatous polyposis, colorectal cancer and other diseases, colonoscopy can be an early detection of the disease, timely treatment, so as to avoid delays in the condition. Familial adenomatous polyposis is an autosomal dominant disease. In the early stage of the disease, patients often do not have any symptoms, which can only be detected through colonoscopy. With the growth of intestinal polyps, patients may have symptoms such as hidden abdominal pain, nausea, vomiting, diarrhea, mucus bloody stools, and intestinal obstruction, etc. In addition, intestinal polyps may also become cancerous. Colorectal cancer is the collective name of colon cancer and rectal cancer. The development of colorectal cancer is related to factors such as heredity, age, environment and dietary habits, etc. In the early stage of the disease, patients do not have any symptom, and it is only when the cancer grows bigger or the cancer appears to be eroded that the patients will have symptoms such as constipation, diarrhea, bloody stools, anemia, emaciation, fatigue, and low-grade fever, etc. Enteroscopy helps to detect the cancer in the early stage. Elderly people can have a colonoscopy once every 3 to 5 years. Elderly people with intestinal polyposis or a history of colorectal cancer should follow the doctor’s instructions for a follow-up examination.