When you're on the toilet taking a shit, and you pick up that huge cup-shaped thing filled with water, wash your ass with it, and the water floods over the toilet, infested with ass juice.
I accidentally shit fountain'd myself yesterday.
by D. Rodriguez October 28, 2010
when poop is dipersed out of your rectum at an alarming pace, much like a fountain
i got so sick, i was a shit fountain
by Johnnnnnnnnnnnnnnnn October 06, 2003