Negative blood test?

In January, I finally went to see a gastroenterologist after years of horrible digestive issues (extremely painful bloating, constipation, etc. etc.). I did my research beforehand and I thought I might have celiac's disease, because once I paid attention to my diet I realized that I got sick after any meal that included bread or pasta. My doctor agreed that my symptoms fit a Celiac diagnosis, and I had the IgA blood test done. The test came back negative. After that, the doctor seemed convinced it wasn't gluten. She told me I had IBS and prescribed me a laxative. The laxative helped me feel a bit better in general, but I still felt sick after almost every meal. So I decided to trust my instincts, and about two months ago I stopped eating gluten completely. I feel SO much better, I have almost no stomach issues, I've stopped getting weird rashes after exercising, I have more energy, less soreness...It's great.

The other week, I got ice cream that had an extremely small amount of flour in it (probably less than a teaspoon). Within two hours I was on the ground crying, the bloating was so painful and I was constipated for several days afterwards. I sent a picture of my swollen stomach to my mom, who was completely shocked, because she thought I was exaggerating my digestive issues. Now she's convinced I have CD and wants me to undergo further testing. She ordered a DNA testing kit for me. I know the DNA tests can only rule CD out, and if they come back positive you need further testing (probably an endoscopy at this point). Am I going to have to go back on gluten for the endoscopy results to be accurate? Is it even worth it to get the diagnosis if it means having to eat gluten for several weeks? Just that small amount of flour was completely intolerable. :( Also, is it likely that if my IgA test was negative, I have CD?

One more random question: can undiagnosed CD cause hair loss?

Do you happen to know how much gluten you have to eat, and for how long before the test? I mean could I eat a piece of bread a day and that would be enough, or do you have to like binge on gluten? It'll be difficult to do this because I'm in college, so I obviously can't do it any time during the academic year because I literally can't stand after eating gluten, and I can't miss classes. I'm hoping 2 or 3 weeks would be enough time so I could start after Christmas and have the endoscopy done in mid January right before returning to school.

I'm realizing that not having a diagnosis is an inconvenience. I'm studying abroad this semester but I can't get dietary accommodations because there's technically nothing wrong with me, since, you know, non-celiac's gluten intolerance isn't a real thing :P So I really hope my Chilean family is understanding of why I can't eat anything with flour in it.

If you have IgA deficiency, the Celiac blood test will be falsely negative.

Consider EnteroLab.com for stool & genetic testing...don't have to be eating gluten to do the test, as long as you've eaten it within the last 12 months.

IgA is one of the types of antibodies the immune system makes. Some people have an error that causes them to be unable to make enough IgA. So when these people are tested for IgA antibodies to something specific, such as gluten or gliadin, the test comes back negative because their body is unable to make enough antibodies to the gluten/gliadin to show up on the test even if they do have Celiac.

To make sure this isn't an issue, ask your doctor for a Total IgA test.

For more info, check out neurotalk.psychcentral.com/archive/index.php/t-105601.html - excellent discussion of testing for Celiac in light of selective or total IgA deficiency...