Conclusive results for gluten intolerance are usually found by putting a patient on an elimination diet to see if eliminating gluten relieves their issues. However, this is not the first step. Blood testing and allergen testing is done first, as elimination diets can be risky if other issues are present. A blood test to determine if the patient has Celiac’s Disease, a severe gluten intolerance, is first done. In some situations a doctor may also suggest an intestinal biopsy.
Celiac’s Disease is relatively rare, so if the patient tests negative for the clinical test for celiac sprue disease, an allergen test is then done. Please note that just because you test negative for celiac disease does not mean with certainty that you still do not have some form of gluten intolerance. It also does not preclude the possibility for a wheat allergy. For more on these distinctions, please read gluten allergy symptoms.