J.D. on the show Scrubs passes out when he has a BM, and it's considered a neurological disorder, not gastrointestinal. I would trust your doctor, it sounds neurological.
It is strange how the digestive system is affecting our head. Problem is the Dr.s don't think so. They call it anxiety.
Excuse the missing letters in some words in my above post. i was typing after getting off the phone with the Dr.s office & I was a bit upset!
It makes it difficult to eat because I'm afraid I will get those horrible symptoms. Like you said, there are so many possiblities of what could be wrong. Good luck, I know it's no fun starting over again especially after you had your gall bladder out.
Thats funny i have something like that but not that serious I get lite head or dizzy when i eat, I had my gallbladder taken out in jan and now i can hardly eat anything. When that happens to me I also shake, sometimes I sweat, but after a couple bowel movements or a couple hours i'm fine. My surgoen told me that my gallbladder wasn't the problem then, so i go to the doc today to start all over again. Theres so many things that it could be I think its wierd how your digestive system has something to do with gettin lite headed.
If you've ruled out anything to do with blood sugar changes and anything neurological going on, have you checked into the possibility of celiac disease? There's a phenomenon that many celiacs call 'brain fog' that's described as being completely out of it, or spacey. Fatigue can also be an overwhelming problem in some.
If anyone in your family (close or extended) has it, you may predisposed to it. You may want to ask family members.