A man was suffering from a stomach ache, so he told his wife who suggested he try the tablets the Doctor had given her for a similar pain.
After taking his wife's tablets for a week, the pain disappeared but he developed two rather tender lumps, one behind each ear. He went to his doctor, showed him the lumps, and explained what had happened.
Whereby the Doctor called him all the fools under the sun, saying, "You stupid idiot! I was treating your wife for a fallen womb, God knows how I'm going to get your balls back down!"