Six-month-old babies with sour stools may be due to indigestion, acute gastroenteritis, lactose intolerance and other reasons. 1. indigestion: pediatric gastrointestinal dysfunction, accumulation of food and other causes of food accumulation in the stomach, fermentation in the stomach to produce a sour smell and thus appear six months baby stool sour. 2. Acute gastroenteritis: pediatric patients with acute gastroenteritis, food fermentation in the stomach under the action of bacteria, resulting in a sour odor and thus the six-month-old baby’s stool acidic odor. 3. lactose intolerance: pediatric lactose intolerance leads to breast milk or milk powder is not fully absorbed, thus appearing six months of the baby’s stool acidic odor. Six-month-old babies, there may be other reasons, it is recommended to go to the hospital, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.