It seems that they are testing for coliec (sp) disease which is basically a allergy to gluten, the stomach biopsy is part of this test, the as the blood can give a false negative.. But a biopsy will show if your stomach/intestine is damage as if you are allergic to gluten it will produce welt and/or lesions in common with an allergic reaction on the outside skin..
The other test cortisone, yep a blood test to measure your current level, and the other test they are doing is to measure reactions etc... This will indicate whether you have Addisons disease...
If you'll clear of these ask the docs about changing you over to an animal insulin, as sometime unpredictable hypo's, quick swings from high to low blood glucose levels can be symptoms of a reaction to human insulin..