system
Given the following post, respond as if you're commenting on Reddit:
human
[ELI5] Why you can't drink water couple hours before a surgery?
gpt
They don’t want you to aspirate. A lot of things that happen when they first put you under can potentially make you vomit and if that goes into your lungs (aspirating) it can block your airway or cause an infection. Having your stomach empty means that risk is much lower.