Fecal matter left in one's ass because they didn't wipe well enough after a dump. Usually results in a second trip to the bathroom after the itchy feeling becomes too uncomfortable.
You're at a friends house where a party is being thrown. You have to take a crap, but you understand that there are going to be people waiting for you to finish quickly. You shit quickly, wipe even quicker, and leave with "unfinished business" that will be attended to later.