In the Penny Arcade RPG On the Rain-Slick Precipice of Darkness, there's one quest that involves giving a scale-model ferris wheel to a "Urinologist" just so he can urinate on it (and give you a jar of urine in return). The act of urination is described in great detail.
And in Episode 3, one of the enemies you encounter are "Rabbites", rotting, zombie-like rabbits covered in blood, with something resembling an intestine wrapped around their necks, and they attack you by coughing up blood. It's a revolting sight, even for a 16-bit sprite.
In "Order of the Stick" comic number 835 Vaarsuvius and Belkar do something truly horrible to a kobold.