re: Crackpot ASOIAF Theories SPOILERS

He was severely constipated...hadn't gone in weeks I think. Plus Oberyn told Tyrion that "Your father can't live forever." I would say it's 50/50 though: half the fans are convinced Oberyn poisoned him, the other half don't believe it. As for me, I think Oberyn poisoned him, albeit very slowly. Pycelle mentions a poison called Widows Blood which slowly shuts down the bowels. Plus the description of Tywin during that scene...his face is green and had some nasty puss leaking out of his body . Oh and his corpse absolutely reaked and rotted faster; basically all the characters commented about the nasty stench.