When one has defecated and the excess of said matter remains on the perineum, mainly occurring when one suffers gastrointestinal upset (Diarrhea)
Better wipe properly, you don't want muddy krudge.
Bidets were invented to prevent Muddy krudge
Holy crap that is spicey, Don't eat too much or you'll end up locked in the restroom with dealing with muddy krudge