The possible causes of blood in stool for a few days and then no blood in stool are: internal hemorrhoids, colorectal polyps, inflammatory bowel disease, colorectal cancer, etc. The treatment can be divided into medication and surgery. 1. Internal hemorrhoids: internal hemorrhoids are one of the most common causes of blood in the stool, mainly manifested as intermittent fresh blood after stool. Asymptomatic patients usually do not need special treatment, symptomatic patients can choose sclerotherapy injection, rubber band ligation, hemorrhoidectomy surgical treatment and other ways. 2. Colorectal polyps: Colorectal polyps are now mostly resected under colonoscopy, and patients are usually advised to undergo pathological examination to exclude the possibility of malignant changes. 3. Inflammatory bowel disease: including ulcerative colitis and Crohn’s disease. Treatment is based on medication to control the disease, according to the condition can use mesalazine, glucocorticoids, azathioprine and other drugs. Biological agents such as anti-tumor necrosis factor monoclonal antibody are effective, but the price is relatively high. 4. Colorectal cancer: Early and middle stage colorectal cancer is mainly treated by radical surgical resection, after which chemotherapy and radiotherapy can be assisted according to the condition to reduce the risk of metastasis and recurrence. For advanced or recurrent metastatic patients, comprehensive treatment is the mainstay, including chemotherapy, radiotherapy, targeted therapy, immunotherapy, etc., such as 5-fluorouracil and bevacizumab. In addition to the above diseases, colorectal infections and colorectal vascular diseases may cause intermittent blood in the stool, so patients are advised to go to the hospital as soon as possible to find out the cause of the blood in time and then provide targeted treatment.