The sadness after a real good poop. Sometimes you poop and its feels like part of you has left and something significant has been lost that can never be brought back. It leaves a feeling on incredible remorse and sadness.
Person #1: Aw, man, I took such a big dump yesterday that it gave me PPBH!
Person #2: PPBH?
Person #1: Yeah, Post-Poop Butt Hurt
Person #2: Dude, PPBH is the worst!