Flaming liquid shit that makes you scream with pain, clench your teeth, grab hard onto the nearest solid object so that you don't get blown away, and wonder how you're still alive when it's over.
My diarrhea is so bad that I couldn't walk for fivedays afterwards.
After what seemed like hours of stomach cramps at school, Jason was finally able to go home and launch his lava-like diarrhea into his beautiful porcelain throne.
Analogous to vomit, exiting from the anus. Often accompanied by a singed asshole.
Random: Do farts have lumps?
Me: Na dude, I think you just diarrhea'd
Random: Mate, diarrhea doesn't have a verb form
Me: I'd be more worried about that shit running down my leg if I were you.