Spitting up in your baby’s sleep is usually a normal phenomenon, but it can also be caused by abnormal conditions, such as indigestion or acute gastroenteritis. 1. Normal phenomenon After a baby eats milk into the stomach, because the baby’s stomach is still horizontal, not conducive to food emptying, and the baby’s pancreatic sphincter development is not perfect, so the baby is usually prone to spit up phenomenon. Usually master the correct posture when feeding, at the same time appropriate to help the baby burp, etc., help to improve. 2. Abnormalities Indigestion: If you don’t feed your baby properly, such as giving your baby too much food at one time, resulting in indigestion, it is usually easy to cause your baby to spit up, accompanied by diarrhea, bloating and other symptoms. Acute gastroenteritis: If you don’t pay attention to hygiene when feeding your baby, causing your baby’s body to be infected by bacteria or viruses and parasites, and suffering from acute gastroenteritis, it will usually lead to spitting up, accompanied by nausea, vomiting, diarrhea, loss of appetite and other symptoms. The baby fell asleep spit up if accompanied by other abnormal symptoms, or frequent spit up phenomenon, should be timely to the regular hospital, a clear diagnosis, in accordance with the doctor’s instructions to deal with, so as to avoid delays in the condition.