5 months old baby has blood in the stool, mostly considered to be caused by enteritis, constipation, allergies, hemorrhoids, anal fissures and other diseases, it is recommended to go to the hospital for examination and treatment after clarifying the cause. Common causes and treatment 1, enteritis: in addition to blood in the stool, but also accompanied by nausea, vomiting, diarrhea, low appetite and other symptoms. Need to improve the stool routine, stool culture and other tests to clarify the type of pathogenic bacteria, follow medical advice to anti-infective treatment, such as amoxicillin, and at the same time need to be symptomatic treatment, such as oral montelukast to stop diarrhea, bifidobacteria to regulate the gastrointestinal flora, oral or intravenous rehydration, etc.; 2, constipation: mostly due to dry stool, easy to damage the anus and intestinal mucosa of 5-month-old babies caused by bleeding, but also accompanied by bloating, loss of appetite and other symptoms. Light attention to adjust the diet, appropriate to eat vegetable juice, fruit juice, parents gently massage the baby’s abdomen can be relieved, if not relieved and has a tendency to aggravate, promptly seek medical advice to be laxative, such as lactulose, in serious cases need enema treatment; 3, allergies: 5 months baby allergic to the addition of complementary foods, will also lead to blood in the stool, accompanied by rash, itching, diarrhea and other symptoms. Need to promptly investigate allergens, as far as possible to keep the baby away from allergic substances; 4, hemorrhoids, anal fissures: if the baby has blood in the stool, accompanied by violent crying, should be alert to whether the hemorrhoids, anal fissures, need to promptly seek medical attention, the incidence of pediatric hemorrhoids is low, physical therapy can be used, the application of compound aspirin when the pain is severe, with constipation using liquid paraffin; pediatric anal fissures available 10% -20% silver nitrate solution 5, other: a small number of children with colon polyps, intussusception can also appear such symptoms, should promptly seek medical attention, serious cases can be treated surgically. Parents need to give their babies proper hydration, intake of supplementary foods containing more fiber, such as various vegetable juices, in order to develop good bowel habits; at the same time need to pay attention to dietary hygiene, bottles, straws and other supplies need to be strictly sterilized.