The main symptoms of black bowel disease are abdominal fullness, constipation and difficulty in defecation, and some patients may experience abdominal pain, nausea and loss of appetite. Black bowel disease is mainly caused by melanin deposition in the colon area. The main cause of black bowel disease is clinically considered to be long-term constipation caused by the long-term use of laxative drugs, such as phenolphthalein tablets and senna preparations. It is common in elderly people with long-term constipation, and in young people it is mainly seen in patients taking long-term weight loss products, such as bowel cleansing and detoxification products. Some of the black bowel disease can develop into colon malignant tumors, in the treatment is no special drugs, but improve constipation can reduce the pigmentation of black bowel disease. The main thing is to improve the dietary structure, such as eating more fruits and vegetables, mainly coarse fiber food, combined with strengthening exercise, improve intestinal motility function to improve constipation.