Reasons why newborns spit up milk frequently It is a common phenomenon for newborns to spit up milk frequently. The main reason is that the connection between the esophagus and the stomach of newborns is not close enough, causing food to easily reflux, and the gastrointestinal function of newborns is not very perfect. In addition, excessive eating, improper eating posture, infant diarrhea, etc. may also cause newborns to vomit milk. During eating, if you don’t burp in time,