Well, the main historical source for the Buddha's death is, unsurprisingly, to be found in the Buddhist Sutras (= sacred texts) which were written in sanskrit long after his death (until then, they were memorized and recited. Something you can actually feel when you read the oldest ones, because their structure is obviously aimed at memorization, with lots and lots of repetition).
The one dealing with the Buddha's death is the Mahaparinirvana Sutra, which exists in at least two versions, the pali one (from the Theravada school, dominant in Sri Lanka and Thailand) and the Mahayana one (from the later "Great Vehicle" schools, which became dominant in Eastern Asia).
The pali Mahaparinirvana sutra says that, during the rainy season, the Buddha, who was already extremely old (he was about 80 years old) suffered from an "illness" causing him "accute pain and deadly suffering". He pondered that it wouldn't be proper for him to die without saying farewell to his community. So he focused on using his willpower to overcome death and somewhat succeeded. The text politely says that "his illness was somewhat relieved". We should understand here, that he wasn't cured at all, of course ...
Interestingly, at this point, the Buddhist version of the christian devil, Mara, appears to tempt the Buddha to hurry to enter into Nirvana, in other words, to die. The Buddha answers that he certainly will die within three months.
It is only after these events that the Buddha went to have his lunch at Cunda's house. There he deliberatly eats the fated meat and gets his fatal dysentery.
So yes, he may have died of food poisoning. Yet, if we are to fully believe the texts, he was obviously already very ill and weakened. In spite of the sutra's insistance that nobody on earth could have survived eating Cunda's meat (hence the instruction to bury it), the Buddha was probably already doomed to die of something which we will never know, for lack of an autopsy.
:lalala:
