The two-year-old baby’s mouth stinks, considering that it may be related to indigestion, oral diseases, constipation and other reasons. 1. indigestion: the baby’s usual unhealthy eating habits like overeating, intestinal flora imbalance and so on may lead to indigestion. Food in the stomach can not be digested and absorbed in a timely manner, after a long time of degradation will produce a lot of gas, which may lead to the baby’s mouth stinks. 2. Oral disease: babies suffer from gingivitis, periodontitis and other oral diseases, there is a lot of bacteria breeding in the mouth. The decomposition of anaerobic bacteria will produce sulfide, which may also cause the baby’s mouth stinks. 3. Constipation: constipated patients have a large amount of metabolic waste in the intestines, which can not be discharged in a timely manner, is also the cause of the baby’s mouth odor. Parents are advised to take their babies to the pediatrics department of the hospital as soon as possible to identify the specific causes for treatment.