The baby three days before the poop out is green, may be due to indigestion, constipation and other factors. 1. indigestion: may be due to the baby’s digestive system is not yet fully developed, if eaten too much will exceed the normal digestive capacity, easy to stagnation, resulting in indigestion, thus the baby three days before the poop pull out is green. 2. constipation: may be due to the milk or milk powder in the nutrients, the baby can not be fully absorbed, and thus stagnant in the stomach, the phenomenon of constipation, resulting in the baby three days before the poop out is green. The baby three days to pull out of the stool is green, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.