when your done in the bathroom and the toilet bowl is blasted with shat. it usually doesn't come off when you flush.
"I walked into Ryan's bathroom to take a leak and there was a nasty shat blast in the toilet"
When somebody shats with such force and liquidity that pieces (or drops) of poop end up stuck to the bottom of the toilet seat.
Since females seldom (if ever) lift the toilet seat, they always tend to let the guy clean it up, even if they did it.
"omg somebody totally shat blasted my toilet"