Please be rude, crude, and socially unacceptable

[wayfaringwordhack]

Someone asked me yesterday to share with her any crude ways of saying, in English, to do one's business, and all I could come up with was "take a dump." I'm sure cruder stuff exists, but I was at a loss to come up with any.

I don't know if I've been away from English speaking countries too long or if I never hung out with the "right" people and actually learned those quaint phrases.

So, if you'd like to enlighten me, so that I might in turn enlighten my curious French friends, please be gross in the comments.