system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why do babies vomit so often?
gpt
The valve that connects your esophagus to your stomach is not fully formed/does not fully close when you are first born. This means that it is much easier for food to come back up.

Also, the manner in which babies feed means that they are more likely to ingest air which can cause discomfort and increase chance of spitting up. Burping the baby after feeding can mitigate this but sometimes you don't always get all the air out.