FYI. From article. It is an infection.
Came here hoping for an answer, sadly don't think this is my case. Gluten/Thyroid is pretty hard to nail down..
"Giardia lamblia, occasionally called “beaver fever,” is an easily treatable intestinal parasite, unlike celiac disease. If you’ve been backpacking long enough, you probably know someone who’s gotten it. Giardia is normally an acute infection that causes diarrhea, horrendous gas, and other intestinal malaise, but doctors can corral it easily with antibiotics. The chronic form of giardiasis is lesser known, however. The friend sent Johnson medical studies showing how chronic Giardia infection can cause celiac-like symptoms. "