Jami` at-Tirmidhi Book 10, Hadith 100
"Sulaiman bin Surad said to Khalid bin Urfutah - or, Khalid said to Sulaiman - 'Did you hear the Messenger of Allah saying: "Whoever is killed by his stomach then he will not be punished in the grave"?' One of them said to the other: "Yes."
The Messenger of Allah said: "The martyrs are five: Those who die of the plague, stomach illness, drowning, being crushed, and the martyr in the cause of Allah"
The Prophet mentioned the plague and said: "It is an abiding punishment or chastisement that was sent upon a group of the children of Isra'il. So when it occurs in a land while you are in it, then do not leave it. And when it occurs in a land while you are not in it, then do not enter it."