Ulcerative colitis is a nonspecific colitis, an inflammatory disease that involves only the colon and rectum in a chronic fashion. The cause of ulcerative colitis is not well understood and is the result of a combination of factors. The disease may be related to genetic factors, immune disorders, and lifestyle habits; intestinal infections may also trigger the disease; in addition, mental factors play a role in the development of the disease, stress, strain, and tension can also trigger the disease; food allergies are also a cause that should not be ignored, eating allergic foods can often cause a relapse, and the disease will improve after the prohibition of such foods. Colonoscopy is the most important screening tool for ulcerative colitis. Colonoscopy can reveal diffuse inflammation of the affected intestinal segment in the colon or rectum, with brittle mucosa, easy bleeding, more mucus exudation, and in severe cases, ulcers and pseudo-polyps-like changes, which can lead to colon cancer in long-term chronic recurrent attacks. In general, the heaviest lesions are in the rectum, and in severe cases, the whole colon can be involved. Patients with ulcerative colitis should pay attention to their diet and lifestyle habits in daily life. In the acute phase, bed rest and moderate activity. Avoid cold, sour, spicy and irritating diet and prohibit alcohol consumption. Avoid exertion stress and anxiety, eat less and more meals. Use medication under the guidance of a doctor. Ulcerative colitis is a long-term chronic disease, you should have patience and actively cooperate with the doctor’s treatment.