If the baby’s stool is black, there are several reasons: 1, dietary factors, the food eaten by the gastrointestinal fluid digestion will appear black stool, such as iron-containing drugs or food containing pigments can lead to black stool. 2, the cause of the digestive tract, if the child is constipated, after a long time will show the discharge of black stool, or due to bleeding disorders of the digestive tract caused by black stool. The child should be observed for abdominal pain, vomiting, anorexia or weight loss, and the child’s stool tests should be combined to clarify whether it is due to bleeding disorders or constipation. 3, due to blood system disorders, such as neonatal bleeding disorder, leukemia, hemophilia or aplastic anemia, etc. can cause gastrointestinal bleeding due to thrombocytopenia or coagulation dysfunction.