HI I Am Preparing To Do A Celiac Blood Test.

HI
I am preparing to do a celiac blood test. To prepare for this I am now again eating gluten everyday for a month, as was requested. Even though I have been watching my intake of gluten over the last number of years, I continue to have tummy problems. As I prepare for this test, I am now not taking my digestive enzymes which I normally do- if I decide to eat gluten or am in a setting which may be suspect. I am however, still taking my daily supplement of magnesium oxide or citrate to have a more regular bowel movement. Is that OK or should I temporarily go off of that as well? The blood test that has been requisitioned for me is under the proteins/serology column. I have just noted that the most reliable blood test is the tTG-IgAtest. Is this the test that I am most likely to have done?