I think I would probably be too afraid to go, too. But I spent 3 months in Mexico as an exchange student many many years ago and I remember that I was really careful about water and stuff but my roommate and I forgot to say "sin hielo" one day and accidentally drank something w/ice in it. We were totally sick.
Also, be sure to keep your mouth closed really tightly in the shower.
I think I'll be fine. I have a strong gut, am bringing loads of snacks in case regular food doesn't sit well with me, and best of all, my pal that my Dh and I are traveling with is an ob-gyn.
It doesn't get better than that!
Lostgirl
Me: 37 DH:40 TTC since 2005. First IVF cycle canceled. 2nd cycle BFP 1/11. DS arrived late 2008. 3rd cycle, U/s 3/7. Devastated. NO fetal pole or HB.