When there is an intense, overwhelming painful cramping in the stomach and abdomenal region that usually ends results in one bent over clutching themselves in pain. Sometimes there are the noises of a weasle running around and screaming to be released, by means of diarrahea. Side effects may include: goosebumps, shivering, crying, cramping, burning of the anus, sweating, and sharting or aka shit farting.
"Oh man, my stomach hurts sooo bad, I think I have a shit weasel running around and wants to get out oooouch!!" and then run to the bathroom for relief.
by Corinne G. May 08, 2007
Comes from Stephen King's book, Dreamcatcher. Humans who eat the alien virus call "byrus" grow an alien weasel in their bowles and when it gets too big it bursts out of their butt.
"Mcarthy's lower midsection was covered in blood as the shit-weasel came out"
by Patti March 01, 2005