Sorry to hear about your experience. We go into these tests as prepared as possible, but some things are out of our control. Although it's a tough pill to swollow when you feel you didn't perform up to your expectations, you shouldn't beat yourself up over something like that. Having terrible stomach pains certainly doesn't = "dumb."
To anyone going into their first exam experience, know that besides diligent studying, etc., your physical wellness is a big part of exam success. You need to control this to whatever extent possible, with the realization that you can't control everything of cousre (flu, stomach pains, etc.). There shouldn't be any big changes in diet, caffeine intake, sleep patterns, etc. in the last days leading into the exam.
I myself made a potentially costly mistake on FAR recently. I tried to do the right things, but I was so distracted about 2 1/2 hours in because I was so hungry, plus I had to use the restroom. My stomach was making rediculous noises and I was squirming in my chair. I was praying that everyone in the room was wearing their headphones so they wouldn't hear. I didn't see anything on this forum about "the guy making rediculous noizes while I was testing," so I guess they did! Make sure you are well fed, but adequately emptied before going in!
FAR- 81
AUD- 93
BEC-
REG-