Melanosis, properly referred to as colonic melanosis, is not serious in itself, but it needs to be taken seriously, and colonic melanosis may carry some risk of becoming cancerous. Colonic melanosis is a benign, non-inflammatory bowel disease, characterized by dark pigmentation of the colonic mucosa. The exact pathogenesis of the disease is not clear, and most of it is due to chronic use of anthraquinone laxatives after constipation. Colonic melanosis can be treated by lifestyle modification and discontinuation of related medications. Lifestyle modification includes eating more food rich in dietary fiber to promote bowel movement, and adopting the habit of regular bowel movement. Discontinue the use of anthraquinone laxatives, such as rhubarb, aloe vera and other plants containing anthraquinone glycosides, as prescribed by the doctor. If patients use stimulant laxatives because of long-term chronic constipation, it is recommended that patients first clarify the cause of constipation and carry out causal treatment. Secondly, try to avoid the use of such stimulating laxatives, you can use polyethylene glycol electrolyte bulk or lactulose and other drugs to assist defecation. At the same time in daily life should also pay attention to moderate intake of food containing dietary fiber, avoid eating only fine grain. It is also important to be active and avoid sitting for long periods of time. Colorectal gangrene requires standardized treatment under the guidance of a doctor and regular review, and people with constipation need to follow the doctor’s instructions to use medication, do not abuse laxatives.