Pronounced "Shy-tiss"
It's a combination of having the shits and the
itis. You go out,
eat big meal from a questionable buffet and spend the rest of the day either
crapping your pants or falling asleep, or worse, both simultaneously.
Gary:
Hey Pete, you ain't looking good.
Pete:
Ug, I ate at Number 1 Super Indian Buffet for lunch. Now I got
the Shitis.
Gary: The what?
Pete: the Shitis. I keep falling asleep whenever I'm not pooping my brains out.
Gary: Shitty.