How long do you have to eat gluten before being tested for Celiac disease?

Hi! How long do you have to eat gluten before being tested for Celiac disease? I got "Hypersensitivity to gluten" diagnosis in year 2014., based on a false negative Celiac anti-bodies test (because I was already on a gluten free diet for 6 months before being tested, wrongfully adviced by my doctor). I now live in Norway and would like to be tested the right way. Could you advise me how to do it? I still have chronic anemia, high thyrod antibodies, but normal hormons, low feritin level. I have been on a gluten free diet since 2014. Thank you in advance for your kind reply!

Since you have been living on gluten free diet for almost 9 years, it will take time before your (potential) celiac disease becomes reactivated and may be diagnosed. The doctor can only diagnose an active celiac disease. I am surprised that you still have anaemia, since your celiac disease should have been “cured” by now. However, there may be other causes for your iron deficiency (?). You should start a gluten provocation period that may last as long as two years. Do this in collaboration with your GP.  You should, as a minimum, eat 2 slices of gluten-containing bread a day for at least 6 weeks before you can expect the celiac disease to become reactivated. Take blood samples to examine the levels of IgA-TG2 to monitor when your celiac disease reappears. The more gluten you consume, the more rapid your celiac disease becomes reactivated. If bread/pasta/pizza etc. is too much for you, you may get some "Gluten flour" that may be added to all sort of foods. You should consume 5-15 gram of gluten per day (one slice of bread contain approximately 2 gr. of gluten).