Baby poop is black is usually related to physiological factors such as eating and pathological factors such as digestive tract. 1. Physiological factors: it may be related to the medicine or food that the baby ingested. For example, if some babies have eaten black food, such as a large amount of “Oreo cookies”, their poop may become black, and if they have eaten iron-rich food or supplemented with iron, their poop may also be black. 2. Pathological factors: gastrointestinal bleeding can also lead to the baby poop is black, gastrointestinal tract has a small amount of bleeding when the poop may be manifested as black, can be seen in hookworm, gastric ulcer, acute gastroenteritis. If your baby’s poop is black and has not recently supplemented iron or eaten black food, you should go to the hospital in time to complete the stool routine, occult blood test and other related examinations and follow the doctor’s instructions for treatment.