Arguments on Death of William the Conqueror

I have never heard of a theory where he died of disease. From everything I've read, he died by stabbing himself in the abdomen with his saddle pommel when he fell off his horse.

December 1086 William returned to Normandy to attack the French King's army(who had mocked William's latter-life obesity as being like 'a pregnant woman').

July 1087 William invaded the disputed Vexin region and with personal emnity, ravaged the surrounding countryside before pushing onwards to violently ravage the town of Mantes, which he breached with little difficulty and proceeded in with vicious slaughter(people were especially shocked by the deaths of two very religious hermits in the town). As it burned, a falling ember caused William's horse to wheel and he ruptured his abdomen(or Uretha?), carried off in great agony to his bed in Rouen but then to St. Gervase priory in Rouen for peace by his men to where his clergy(some were also physicians)declared the king was dying.

Death of William. For five weeks he held on surrounded by(at times) sons Wm and Henry, Robert of Mortain, and when Wm died(Sept 9th), his attendants present  either rode off to secure their own possessions, or they "seized the arms, vessels, clothing, linen, and all the royal furnishings, and hurried away leaving the king's body almost naked on the floor of the house" in fear of Wm's nobles & men becoming renegades without their master's iron discipline! Rouen was in general panic, reeling about as if drunk(acc. to Orderic)there was a fire in the town and the streets were chaotic panic as people realised that a lynchpin had been removed. The clergy of Rouen saw to it that Wm's body was carried through the riotous streets and via river to Caen to the Church of St.Stephen to bury Wm, attended by odo, freshly-released from gaol on Wm's last will. But, trying to force his body into the small coffin, his putrefying corpse burst open, emitting a foul smell, and only the hardiest retainers finished the job.