The place where one goes when in alot of trouble. Usually the kind of trouble of their own creation and the situation has drastically deteriorated.
A major stuff up.
Oh fuck, I can't believe you forgot to put the car tyre back on properly; we are really up Shitter's Ditch now.
A: "Where's Barry?"
B: "He cheated on his wife and is in hiding"
A: "Oh, he must be up Shitter's Ditch then."