What is Shit-up?
1.
Working out vigorously with full bowels, then trying too hard to get that 'last' sit-up. At least your whole anus didn't pop out, like has happened to some unfortunate weight lifters.
Weight lifter: *pant* *pant* uuHHUNNGHHT! *sploosh*
Random hot girl walking by: Aww gross... did you just shit-up?
See
2.
when a huge dump comes flying out your dunghole so fast that you are lifted off of the toilet seat
Guy: Oh shit here it comes!
'turd shoots out like a bottle rocket'
'guy's head gets stuck in ceiling'
Guy: Damn i hate doing those shit-ups.
See
