In the final stage the body goes into convulsions, rigid and jerking back and forth (preceding this stage, a zombie-like state) then severe bleeding from the noise and anus.
The virus is a predator and is basically liquidating your innards, with the intestines sloughing-off their linings, untii you are bled-out enough that you become comatose and then die.
Lovely, huh?
And when you die, what’s left of you isn’t much more than a skinbag full of bones and liquefied guts, and a lot of amplified virus looking for a new home.