An ulcer in the intestinal mucosa found by e-colonoscopy does not necessarily mean cancer. The most common disease with ulcers found under colonoscopy is ulcerative colitis, and cancer of the colon and colonic tuberculosis are also possible, which requires biopsy under e-colonoscopy. In the case of ulcerative colitis, the stool is usually mucopurulent and bloody, and the onset of the disease is usually in young and middle-aged people. After the diagnosis of ulcerative colitis is confirmed, it needs to be regulated with medications such as sulfadiazine or mesalazine plus neurontin, and hormonal medications can be used when the symptoms are severe. If it is a tumor of the colon, it needs to be treated by surgery or chemotherapy as soon as possible. If it is tuberculosis of the colon, anti-tuberculosis treatment should be given in the department of infection medicine, and the course of treatment is usually more than one year. When an ulcer is found by colonoscopy, it is important to eat less spicy, fried and other irritating foods and to abstain from alcohol.