Blood in the stool of a 9-month-old baby is usually caused by food allergy, acute enteritis, anal fissure and other reasons. Parents need to promptly take their children to the hospital for stool routine or abdominal ultrasound and other examinations, under the guidance of professional doctors for symptomatic treatment. Common causes 1, food allergies: commonly caused by food protein induced proctitis, colitis syndrome and other diseases. Usually bleeding from the rectum and sigmoid colon, which can be observed with the naked eye as bloody stools; 2, acute enteritis: if the baby’s intestines are infected with more invasive bacteria, such as Shigella, causing bleeding due to damage to the intestinal mucosa, resulting in blood in the stool; 3, anal fissure: mainly due to the baby’s weakened gastrointestinal peristalsis, constipation, dry stools, etc., stimulating the skin at the anus, resulting in blood vessel rupture and bleeding; 4, other factors : such as hemorrhoids, perianal abscess, rectal polyps, etc., can also lead to bleeding in the baby’s stool. When the baby has blood clotting mechanism disorders or anemia and other blood system diseases, there is also the possibility of rupture and bleeding. Treatment measures 1, avoid eating allergic food: the disease caused by food protein induction, when adding supplementary food to the child, avoid eating allergic food; 2, medication: stool blood cause of acute enteritis, follow medical advice to use cephalosporin antibiotics for anti-inflammatory treatment; 3, treatment of wounds: wash the fissure with saline, follow medical advice to use erythromycin ointment to prevent bacterial infection in the fissure, also through Surgical treatment of rectal polyps; 4, daily care: pay attention to the timely supplementation of nutrition to the baby, you can add some easy-to-digest food, such as pumpkin porridge, millet porridge, etc. Parents need to pay attention to the amount of bleeding and accompanying symptoms when the child has blood in the stool, and be alert to the appearance of anemia and hemorrhagic shock. In addition, if the baby takes iron-containing food, it may lead to black spots in the stool, which parents may mistake for blood in the stool, so they need to pay attention to the distinction.