A power phrase for skid marks in your shitter. A.k.a. the stain left in the end over a toilet bowl after defecating.
"Who left the shit wrinkle in the jacks, I'll punch who ever it was in the barse!", chortled Billy
When your in the bathroom stall and you hear someone taking a shit. It sounds like a wrinkle coming out of their ass.
I was in the bathroom and the girl in the stall next to me made a shit wrinkle