system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: I wipe my bottom very well until the TP comes back clean - without fail 20 minutes later I have to "re-wipe" - what the hell is going on?
gpt
It's because you are wiping away the poo on your butt, the TP is absorbing the moisture as you wiping, leaving behind dry poo that won't wipe away any more.

So when you walk around for 30 minutes or sit, with your butt cheeks together, they release moisture and re-moistening the dried poop you left behind, giving you mud butt.