Three-month-old babies with dark green stools may be related to the mother’s diet, intestinal infections, indigestion and so on. 1. mother’s diet: breastfeeding, if the mother ate more green food and food with high iron content, the baby may appear dark green stools, you can observe if only the color changes, the stool does not have a sour smell, this situation is normal. 2. Intestinal infection: baby intestinal bacterial infection, may cause abnormal stools, dark green stools, may also be accompanied by diarrhea symptoms. 3. indigestion: the baby’s digestive function is relatively weak, if the baby’s diet is not regular, eat too much or eat too little, may cause dark green stools. Three months baby dark green stool, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.