Shit casserole involves making a bowel movement (a.k.a. dropping a douce, docking a sub,
taking a shit, etc) into a portable waste
receptacle on top of a
previously deposited bowel movement, or poop. This process is repeated and mixed with urine (a.k.a) piss, and is left to rot in stagnant heat for days. Served fresh with a side of vomit.
This term can be applied to people who inherit a mix of undesirable qualities.