It’s not really something that gets discussed much, but I’d assume that when a person dies, their various sphincters etc would relax and stop holding in what they had hitherto been holding in.
So do people poop themselves when they die, just for a bit of final indignity? Or does it depend?
From Coroner Stories, or My New Nominee for Most Simultaneously Appalling and Riveting Place on the Internets:
Geeze, I would hope not. “He… he CAME BACK FROM THE DEAD JUST TO PURPOSELY SOIL HIMSELF!”
After reading the descriptions of some last meals, I wonder how much of a clean up there is in the death chamber.
And it made me laugh to find a web state entitled “Dead Man Eating.”
Arthur Conan Doyle killed off his most famous character, Sherlock Holmes, in the short story, The Adventure of the Final Problem. Holmes and Moriarty fall to their deaths into a gorge. Apparently the fall caused such considerable damage to both men, Dr. Watson was unable to perform adequate autopsies. This meant Watson was unable to include his dear friend’s death and autopsy in his study of drugs and the human body. Watson was unable to test his theory that prolonged use of cocaine may have had a binding effect with respect to defecation, specifically upon death.
And with his unfortunate demise was born the well known phrase, “No shit, Sherlock!”
Awful, Duckster, just awful! 
Kimstu’s cite is correct. I’m a cop, and I’ve seen a lot of dead bodies. In only a few did the bowels empty. In fact, we just had one yesterday (woman took an overdose of pills).
While I have seen the occasional death with incontinence, most of the time there’s nothing.
St. Urho
Paramedic
My grandfather was the local mortician in a small town and my dad helped him as a kid. Dad told a story of moving a dead body and it audibly moaned. Scared him (almost) to death!
Post-death urination is more common than defecation because when the urinary sphincter relaxes, urine can easily leak out if the bladder is full. But defecation generally takes contractions of the bowel muscles to push fecal matter out. Leakage can happen, especially when a body is moved, but it’s less common than urination.
Based on conversations with a school friend, whose family had been morticians for 3 generations. Teenagers ask questions about such ‘gross’ topics.
Much more common is fluids from the stomach purging out the mouth and nose. Worst smell ever. Fun stuff like this, along with the occasional defecation, moans, and death farts usually happen when the poor bastard (like me) rolls them on their side to wrap them or place them in a bag.
I’ve heard that defecation after death is often associated with cases of hanging or strangulation.
Can’t vouch for the reliability of the site, but here’s some information about the process in relation to hanging deaths: Bodily Functions During Hanging.
I’ve also found a reference to this phenomenon in a more scientifically-researched source, Schaum’s Outline of Theory and Problems of Biology. As seen on Google Books (page 223, in case that link doesn’t take you directly there) one finds this: “Defecation is not completely involuntary, except under extreme circumstances such as execution by hanging or overwhelming fear. In such cases, it is the massive stimulation of the vagus nerve that causes defecation and, usually, urination as well.”
Lastly, I might note (once again departed from a rigorously scientific document) that in The Godfather, Mario Puzo makes repeated references to postmortem defecation when describing whacked victims–e.g., Carlo after he gets garroted (and stinks up the whole car)–details that Coppola mercifully spared us in the film version.
OK, I laughed. Well done.
I was present at the recent demise of my mother. She did not… erm… “soil” herself at death, nor for the several hours afterward until the cremation people can to pick up her mortal remains. Granted, that’s just one example, but it proves it does not always happen.
Yeah, there’s a hack SF writer or two who spread this nonsense about animals, including humans, having “a reflex evolved to make the corpse unappetizing to scavengers.” How the hell a reflex is supposed to get selected when it only manifests after death is a problem that never gets brought up…
I concur with Thalion and St. Urho.