Thanks for the pointer. For years I put up with being "lactose intolerant". Any milk resulted in cramps, gas and diarrhea. Last year I discovered that lactase is made by the tips of the villi in the small intestine. If you're gluten intolerant, the tips get nailed first and bingo! you're lactose intolerant. I've been fiendishly careful to keep the gluten out of my diet and my reward has been a total reversal of the lactose intolerance. Sometimes I get exposed to gluten by unintended consumption associated with some restaurant food. The impact is observed the following day with my insides a total wreck. It takes about 3 days to completely recover from a small exposure.
BTW, the potato patties at McDonald's are OK ~ no breading on them and they don't deep fat fry them in anything that's been used to fry a breaded product.
In the afternoon, though, they all fry those breaded fish things in what we all hope is the third vat to the right ~ but sometimes they screw up and drop them into the french fries vats.
I know it every single time (within half an hour) if I eat frenchfries.
The prophylaxis here is to instruct the cooking staff, in Spanish, English and Farsi, HOW TO COOK THE FISH.
Then, don't buy the fish because the breading is a killer.
Thanks for the tip on the lactose. Didn't help me. Still don't have enough production of lactase to make a serious difference. However, yoghurt and saurkraut, with meals, works fine.