system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it that if you eat something that disagrees with you, it seems to go "straight through you" even though it takes several hours to digest?
gpt
But that's the thing, if you have diarrhea, it doesn't take several hours. Your body wants to get rid of whatever the offensive thing is, as fast as it can. So it takes liquids FROM your body, to flush out the contents of your stomach and intestines, so you poop it out as fast as possible.

In a regular poop, your body is taking the liquids from what you ate and using those in your body for good things. That takes more time to digest but it means you're getting all the nutrients and your body is happy.