The baby breastfeeding green poop is considered to be caused by bacterial enteritis, indigestion or other reasons. 1. Bacterial enteritis: Bacteria enter the body and cause enteritis in the intestinal tract, affecting the physiological function of the gastrointestinal tract of the organism, resulting in an increase in the number of stools, mucus in the stools, and the baby’s green poop. 2. Indigestion: Because the baby’s digestive system is not well developed, the gastrointestinal peristalsis is slow. If breastfeeding is frequent, resulting in the baby’s intestines can not be fully digested and absorbed, the symptoms of green poop will occur. 3. Other reasons: the mother eats more iron-containing food, the baby ate breast milk, the stool will be green. If you can not determine the cause by yourself, you should go to the hospital in time, and remember to use your own medicine to avoid delaying your condition.