Babies spitting out milk may be caused by gastroesophageal reflux, pneumonia, acute gastroenteritis, intracranial infection and other factors. 1. Gastroesophageal reflux: because the infant gastroesophageal function is not well developed, so it is easy to come back up after eating milk, parents are advised to burp the baby properly after eating milk. 2. Pneumonia: babies often have atypical clinical manifestations of pneumonia, can appear spitting and choking, spitting bubbles performance. 3. Acute gastroenteritis: the baby acute gastroenteritis will also appear in the case of spitting milk, but also may be accompanied by diarrhea symptoms. 4. intracranial infection: intracranial infection of the baby may be due to increased intracranial pressure and the baby spit up, often accompanied by poor mental health, fever, lethargy and even convulsions. There are many reasons why babies spit up, and it is recommended that if a baby spits up, he or she should seek medical attention to avoid delaying the condition.