Blood in the stool is often caused by the following reasons: 1, enteritis: when patients eat a lot of greasy food, drink a lot of alcohol, or eat spicy food, it may damage the intestinal mucosa and cause blood in the stool. The symptoms can gradually improve. 2, intestinal malignant tumor: such as colon cancer, you need to go to the hospital as soon as possible to improve the relevant examination, such as blood routine, tumor markers, abdominal CT, colonoscopy, etc. for clarification. If it is the disease, radical resection of tumor is needed, together with lymph node dissection, and later chemotherapy, targeted drug therapy, Chinese medicine treatment may be needed. 3, intestinal malformation vascular rupture: colonoscopy, angiography, etc. are needed to clarify.