One's inalienable, universal right to shit wherever one pleases, whenever one feels the need. Shitter's rights are based on "nature's call" and thus cannot be withheld by any restaurant, coffee shop, hotel or other establishment who tries to claim that toilets are supposed to be for customers only.

Not to be confused with "squatter's rights," which is one's right to live somewhere that has been abandoned. Though one can surely claim both shitter's rights and squatter's rights simultaneously. After all, you have to squat to shit so you're already halfway there.

when you're hungover as shit after a spending a night drunk as a skunk