Well, it's a very rare occurrence, but I got glutenized a few days ago. Yucko. It happens to all of us occasionally. I ate a frozen dinner that listed only soy and milk as allergens and read the label really well, but either cross-contamination or something snuck in. Yucko.
I'm not merely sharing my tummy ache for the ick factor but because I have a palliative treatment for glutenization. It's not a miracle cure. You'll still be sick, but it's better than nothing.
As soon as you figure out you've accidentally ingested some gluten, take a dose of Pepto-Bismol and a couple Simethicone (Gas-X) tablets. You'll still have some tummy cramping, but it won't be as bad.
In addition, avoid all NSAIDs (non-steroidal anti-inflammatory drugs, like Advil, Motrin, Aleve, any generic ibuprofen or naproxen, prescription COX-2 inhibitors, even aspirin, etc.) because these make the gastrointestinal lining more permeable (leaky), thus increasing the amount of gluten available to the immune system for a reaction. Avoid NSAIDs for several days. If you want a pain killer, stick to Tylenol (acetaminophen.)
One good thing about getting glutenized: I can't believe that I used to feel like that all the time. I feel so much better now that I stick to a GF diet.