system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do babies, who drink only milk, create solid waste?

Edit: To clarify, I'm asking about human babies drinking human breast milk.
gpt
Babies fed only  breastmilk don't really have solid waste. It's Not a solid consistency until you start them on solid food and even then it doesn't get solid for a while.  Milk itself has solids. Solids consist of fats and proteins. Some are digested some are not. You will also get volume from bacteria that live in the gut.