Fainting
I haven't had surgery, yet, but I've been known to faint. Usually it was because I had not eaten or was dehydrated. Are you sure you're getting enough protein & water? If you're drinking caffinated beverages (coffee, tea, colas) just remember that they can actually cause dehydration so you may need to decrease them & increase other non-caffinated liquids (water, Crystal Light, etc.)
Good luck - I hope it turns out to be something easily remedied!
Vickie J.
It could also be your sugar levels dropping. I have been hypoglycemic most of my life and have to make sure I eat something every couple of hours. If I have something with too many carbs my sugar levels will eventualy plumid down and if I don't eat something right away I will pass out. Just something to keep in mind when you go to the doctor.