4-month-old babies have blood in the stool, pay attention to the following situations: 1, if the bleeding is accompanied by skin bleeding spots, pay attention to whether there is thrombocytopenia or coagulation dysfunction caused by bleeding, this situation is more common in gastrointestinal bleeding.2, if the baby stool is relatively dry, especially if there is constipation, can cause anal fissure resulting in bleeding, this bleeding is usually fresh blood, not much.3, Also pay attention to the baby food allergy, breastfeeding and mother’s diet, milk feeding is common milk protein allergy, this allergy can cause intestinal mucosal damage leading to bleeding, usually the amount is not too much, often easy to repeat episodes. 4, if the baby has blood in the stool, accompanied by diarrhea or pus and blood stools, but also pay attention to invasive bacterial infections, or intestinal viruses damage to the intestinal mucosa caused by the bleeding.