Remember in Truman Capote's "In Cold Blood"? One of the criminals to be hung was worried he'd poop his pants.
Capote's subjects Richard Hickock and Perry Smith were being prepared for the gallows, along with another critter, by the name of Andy...
Hickock or Smith: Hey, Andy! Does it tell anywhere in them books what happens when you make the drop?Andy: Well, your neck breaks ... and you crap your pants.
Hickock or Smith: The trouble with you, Andy, you got no respect for human life ... not even your own.
Thank you.
Later on, when they were fixin' to string Smith up, he said something to the warden or one of the hangmen about not wanting to "mess himself." But I forget what the warden (or whomever) said in reply.