Here is some useful information about Guts and Balls:
Guts & Balls...

There is a medical distinction. We've all heard about people having guts or balls, but do you really know the difference between them? 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 fatty.'

I hope this clears up any confusion on the definitions.

Medically speaking, there is no difference in the outcome, since both ultimately result in death.