Abdominal pain and diarrhea, combined with black stools, are benign and commonly associated with acute hemorrhagic enteritis of the small intestine, the etiology of which is unclear. Treatment is mainly by broad-spectrum antibiotics combined with metronidazole to inhibit the growth of anaerobic bacteria in the intestine. In severe cases, fasting should be given to allow the intestine to rest adequately. Ulcerative colitis is common, with abdominal pain, black stools and diarrhea. The conventional treatment for ulcerative colitis is to take pentosalicylic acid preparations, along with hormonal enemas such as hydrocortisone enemas. If you have colonic polyposis, especially familial polyposis. Usually there is also abdominal pain, diarrhea, and black stools. It is recommended to have a colonoscopy first, and after the diagnosis is confirmed, it can be treated by endoscopic surgery. It is also common to have malignant tumors of the colon. Malignant tumors of the colon usually cause changes in bowel symptoms and can result in black stools. Less common are malignant tumors of the small intestine, which can be diagnosed and examined through colonoscopy. The oral treatment is usually chemotherapy drugs, and it is necessary to determine the plan and course of medication according to the specific plan of the individual.