Question
The baby is 40 days old and has been fed formula milk since birth, without breast milk. The baby often vomits after feeding, sometimes spitting out whole milk and then vomiting again after some time. Occasionally, there are purulent substances resembling brain matter. When giving water after feeding within an hour, the baby even vomits the milk. After feeding, the baby is also held upright to burp, and sometimes burping doesn’t result in vomiting, but other times, a large amount of vomit is produced. This condition has persisted for several days, and the baby has not gained weight.