The symptoms of breast milk diarrhea in infants are as follows: 1. In light diarrhea, the stool is generally less than ten times a day, the stool is thin and watery, and there are milk flaps in the stool with a sour smell, sometimes with strips of clear liquid. The baby does not have fever, no obvious pain and crying, normal spirit and good appetite. 2, heavy diarrhea symptoms more than ten times a day, less urine and poor mental state, with symptoms of dehydration, should promptly take the baby to the hospital for treatment. 3, prolonged diarrhea, because of the long course of the disease, the baby can appear malnutrition, weight gain.