So I messed up. I was finally sold on the "eat gluten beforehand" and ready to go in and get all my testing finished two Fridays ago.
And then I got sick. Not glutened sick but flu sick and decided in my 102 fevered state that it would be better for me to heal if I took gluten back out. I was also stuck in my gluten-free apartment for days and as a result of only eating gluten-free grains and fruit for a few days I passed out twice on the morning of my appointment with the gastro. I had to call and say I couldn't make it because my vision was spotty and I was still not able to sit up without severe dizziness when I was supposed to drive to the appointment. I got it rescheduled for this coming Friday so that's back on track. The only issue is that when I was home for spring break last week, I got slightly cross contaminated either from the 20+ year old waffle iron at home or a local ice cream shop (though they took all necessary precautions for me). This was after a week and a half of being totally gluten free. My reaction was bad enough, coupled with the flu recovery, that my parents were close to buying an extra ticket and flying with me back to school. I looked awful, was completely nauseous and had the normal bowel movement issues (not full D but close).
So here's what I'm worried about now. I had such a bad reaction to being cross contaminated, not even eating straight gluten. If the Dr. says I should still do the biopsy and that I need to go back on gluten, I'm at the point in my semester where I can't handle having the brain fog (I'm still in a fog from the flu) and needing to stay that close to a bathroom all the time. I have no idea how I lived like that before though I think I caught the full blown celiac's pretty soon after that switch got flipped.
What do I do? Going back on gluten could jeopardize my grades with the extra time I have to spend resting and recovering and the brain fog kills my response time (I have timed oral drills in Russian). I'm also in the last planning and organizing stages for my dance performance in a few weeks which increases my stress levels to the point that eating any gluten or junk in general also makes my IBS act up, which renders me unable to move: not so good for the dancing.
I generally say stay on gluten until the endoscopy is complete. In this case I think you need to do what is best for you...if you are having horrid reactions to CC I would not intentionally eat gluten again. I would have the endoscopy done. While remaining on gluten gives the best possible chance of accurate biopsy -- it is still completely possible to have visual damage, positive biopsy or other evidence in the digestive system of celiac disease.
Don't put your whole semester in jeopardy for the possibility of a better endoscopic result -- at least this is what I would advise my own college aged children.