The word bowels appears 37 times in the King James Version of the Bible. But only one passage connects it to a disease (2 Chronicles 21:15–19).
King Jehoram was an evil king. God punished him with a long and painful disease in his bowels (his intestines). The disease could not be cured. After two years, his intestines came out of his body, and he died in great pain (verse 19).
This may have been a disease like colon cancer or an inflammatory bowel disease (a disease that causes swelling and pain inside the intestines).
The only deadly disease of the intestines in the New Testament also happened to a king. In Acts 12:21–23, King Herod became sick and died. The historian Josephus says Herod was 54 years old and had strong pain in his stomach for five days before he died.
He may have had a blockage in his intestines. This could have been caused by roundworms (a kind of parasite). During the sickness, roundworms may have come out of his body. Or people may have seen maggots (fly larvae) on his dying skin. This may explain why Luke wrote that Herod “eaten by worms and died.”