2 Chronicles 21:12-19:

And there came a writing to him from Elijah the prophet, saying, Thus saith the LORD God of David thy father, Because thou hast not walked in the ways of Jehoshaphat thy father, nor in the ways of Asa king of Judah,
But hast walked in the ways of the kings of Israel, and hast made Judah and the inhabitants of Jerusalem to go a whoring, like to the whoredoms of the house of Ahab, and also hast slain thy brethren of thy father’s house, which were better than thyself:
Behold, with a great plague will the LORD smite thy people, and thy children, and thy wives, and all thy goods:
And thou shalt have great sickness by disease of thy bowels, until thy bowels fall out by reason of the sickness day by day.
Moreover the LORD stirred up against Jehoram the spirit of the Philistines, and of the Arabians, that were near the Ethiopians:
And they came up unto Judah, and brake into it, and carried away all the substance that was found in the king’s house, and his sons also, and his wives; so that there was never a son left him, save Jehoahaz, the youngest of his sons.
And after all this the LORD smote him in his bowels with in incurable disease.
And it came to pass, that in process of time, after the end of two years, his bowels fell out by reason of his sickness: so he died of sore diseases. And his people made no burning for him, like the burning of his fathers.

Notes on 2 Chronicles 21:12-19:

After reading this passage, you can’t believe that God sends sickness to His devout worshippers as a device to build character or teach lessons!  How could it be clearer?  Sickness is a curse and a judgment.  That is why Jesus had to bear our sicknesses for us, so that we would not have to partake of this judgment for sin the way many did in the Old Testament, including the king in question above.

See also:

Sickness as Chastening and Judgment in the Old Testament
Condition: Tumors