I think i have celiac disease. what proves it?

Upper GI scope.: Which is called an EGD. A biopsy of the small bowel mucosa is confirmatory. A blood test before that can help, but the EGD biopsy is the acid test.

Blood and Biopsy: Most providers will start with serology testing of tissue transglutaminase (TTG). If positive or if you have >%% probability of having celiac disease the next step would be an upper endoscopy (EGD) and biopsy. Hope this helps. God Bless