Baby drinking breast milk diarrhea may be caused by baby indigestion, lactose intolerance, protein allergy and other reasons. 1. indigestion: baby eating breast milk diarrhea may be the baby’s digestive system is not fully developed, the digestive tract of the beneficial bacteria content is relatively low, the digestive ability to a certain extent is limited, if eating too much, diarrhea, diarrhea may occur. 2. Lactose intolerance: babies drink breast milk diarrhea may be lactase deficiency, resulting in lactose intolerance, especially after eating dairy products, may produce abdominal pain, bloating, diarrhea and other symptoms, resulting in babies drink breast milk will have diarrhea performance. 3. Protein allergy: the baby drinking breast milk dilution may be on the breast milk protein allergic reaction to the digestive symptoms, may appear nausea and vomiting, abdominal pain, diarrhea and other symptoms, so there will be drinking breast milk dilution symptoms. There may be other reasons for a baby to drink breast milk and diarrhea. If your baby has breast milk and diarrhea, it is recommended that you consult a doctor in time to clarify the cause of the illness and then take the appropriate treatment plan under the guidance of the doctor.