Term used to describe a situation where someone became so overcome with a feeling that they not only lost control of their bowels, they did so on a magnificant scale and let a squareunit drop down. See brick it.
He thought it was funny, so I put an AK in his face and he shit a brick.
A term used to express a state of anger or rage. Usually used in post-conflict chatter. To shit a brick would be insanely painful, hence the pain portrayed in the word.
Dude. My girl caught me playing video games instead of feeding the baby for the 4th time! She almost shit a brick on me.