snap a fish
Pinch a loaf; drop a stool; take a dump.
Damn. My guts are about to burst. I gotta snap a fish!
Snapped Off A Big Fish
A shit of both volumetric and cohesive magnitude that terminates with a blunt end upon exiting the anus, leaving little if any residue in its wake.
Dude, I thought my crap du jour would be a total dumpgasm. But since I snapped off a big fish, I won't be needing the toilet paper after all.