In an effort to keep you informed, the definitions are listed below:

GUTS - Is arriving home late after a night out with the guys, being met by your wife with a broom, and having the guts to ask: 'Are you still cleaning, or are you flying somewhere?'

BALLS - Is coming home late after a night out with the guys, smelling of perfume and beer, lipstick on your collar, slapping your wife on the butt and having the balls to say: You're next, Chubby.'

I hope this clears up any confusion on the definitions. Medically speaking there is no difference in the outcome.
Both result in death.