I actually did go gluten-free for about 7 days prior to the biopsy (yeah, that was dumb). When I had my GI appointment, she had me go back on gluten for 3 weeks prior to the procedure, which I dutifully did.

She said I was extremely uncomfortable during the procedure, more so for the colonoscopy than the endoscopy/biopsy. I don't think she said outright that it prevented her from getting good samples, but she did say that it might make sense to repeat the procedure in a few months if the genetic test comes back positive, or if the gluten-free diet produces a positive result (of course with appropriate gluten-challenge beforehand). She said that if we do that she'd give me full anesthesia so that she can get further into the tract for samples.

I would certainly consider asking for another interpretation of the biopsy. Do they actually keep them around for that kind of thing? Where would I request it to be sent?

Thanks very much for your insight, carbocation.