Acronym for Diarrhea Upper-Lip Sweat.
The perspiration that accumlates on the upper lip while taking an intense shit (normally of the diarrhea variety).
"Hey Eric, why is your lip all sweaty? I bet you were just out golfing."
"Nah, I have DULS. I was just crapping out Taco Bell for the past 10 minutes."
Andrew's DULS got so frequent that he brought a tissue to the bathroom every time.