Blood in the stool of a 5-year-old child may be caused by enteritis, anal fissure, colon tumor, etc., and should be promptly consulted to identify the cause of the disease. 1. Enteritis: enteritis is an inflammatory reaction of the intestinal tract caused by intestinal bacterial, viral and other pathogenic microbial infections or dietary stimulation, immune damage and other factors. Patients may have pus and blood in the stool, accompanied by abdominal pain, diarrhea, nausea, fever and other manifestations. 2. Anal fissure: anal fissure in children may be caused by congenital anal deformity, trauma and other causes of anal stenosis, etc. Patients usually see a small amount of blood during defecation, or drops of fresh blood, accompanied by pain, constipation and other symptoms. 3. Colon tumor: Early colon malignant tumor has no obvious symptoms, with the development of the disease, patients can appear defecation habit change, stool shape change, accompanied by mucus, pus and blood stool. Usually, fecal occult blood test is a positive result and a source of clues for early diagnosis. A 5-year-old child with blood in the stool should be seen promptly for a definitive diagnosis and, if necessary, appropriate treatment by a physician.