Common causes of foamy stool in babies include improper diet, lactose intolerance, and may also be caused by other pathologic factors, such as enteritis. 1. Improper diet: Breastfeeding mothers or babies eat foods with too much sugar or starch, which will increase the burden on the baby’s digestive tract, react with the bacteria in the intestinal tract, produce a large amount of gas, and give rise to symptoms of indigestion, which can easily cause foamy stools in babies. 2. Lactose intolerance: due to the intestinal baby lactase secretion, or congenital lack of, or reduced activity, resulting in the intestinal tract can not be completely digested to break down lactose, producing a large amount of acidic gas, resulting in bloating, diarrhea, and other symptoms, the stool is foamy. 3. Other pathological factors: the baby’s immunity is poor, easy to suffer from bacterial infection leading to acute enteritis, resulting in weakened intestinal digestive function, low activity of digestive enzymes, abdominal pain, diarrhea, crying and other symptoms, and sometimes there are symptoms of indigestion such as foam in the stool. Foamy stools in babies may also have other causes, it is recommended to go to the hospital in time for relevant examinations to clarify the cause of the disease and then actively treat the symptoms.