This happens when you hit the stall about a quarter second before you shit your pants, not having time to sit down all the way on the seat thus projecting fecal matter shit all over the bowl, seat and floor.
Dude, let me toss back a few humunga chungas and I'll show you how to fuck up the bowl!
Also can be used in shorter term of simply “Eat a bowl.”
In East Texas slang originated in the Post OakSavannah used to show disgruntlement and frustration. Normally used as a last-minute saying being giving up.