Newborns with blood in the stool may be related to milk protein allergy, or may be caused by intestinal diseases, coagulation function abnormalities and other reasons. 1. Milk protein allergy: some newborns are prone to milk protein allergy due to immature immune system development and poor intestinal development, leading to intestinal flora imbalance and frequent diarrhea, which may cause intestinal wall damage, and may show blood in the stool. 2. Intestinal diseases: commonly seen in intussusception, intestinal torsion, intestinal polyps and other diseases, which may lead to damage to the intestinal mucosa of the child, resulting in blood in the stool, which may also be accompanied by abdominal pain, diarrhea and other symptoms. 3. Abnormal coagulation function: some infants have abnormal coagulation function, such as thrombocytopenia, vitamin K deficiency, etc., which may cause intestinal bleeding, thus showing blood in the stool. Newborns with blood in the stool may also be related to other factors, it is recommended to take the child to the regular hospital as soon as possible, through the improvement of relevant examinations, diagnosis of the cause, and then give targeted treatment.