What would you do if you were carpooling and you had diarrhea or gas? Seriously, what would you do???

Explain to the driver that you feel sick, stop at a gas station and relieve yourself.

Trust me, that's the best scenario!

Yes, the best answer would be to stop at a rest area. You may be a little bit embarrassed to explain the problem but wouldn't you be even more embarrassed if you had an "accident" in the seat of the car???

I'd ask them to stop at a rest area or Mcdonalds or something and excuse myself. If I was gonna be a while, I wouldn't want to make all of the others late, so I would tell them to go on without me. I'd call in to work and tell them I was ill, and then I'd call a cab or take the bus back home.

The answer to this depends a lot on the people you car pool with. Like with my friends or co workers who are very laid back, I would give a warning. Usually in the form of lame joke role, down the window and let it rip. We would have a laugh and go on about our business.

In England: keep some 'Beeno' handy.

Secondly, excuse yourself!