I have been gluten free for 3 weeks, will this affect my endoscopy results?

It may: If you have celiac disease, being on a gluten free diet can interfere with testing. Biopsies can look normal. You should be on a full diet containing gluten for at least 2-3 months prior to scope. Gluten should not interfere with testing for other diseases.

Maybe...: If you have celiac disease (gluten sensitive enteropathy) then the villi (finger-like cells) that line the intestine shorten when visualized under the microscope. Following a gluten free diet allows the villi cells to grow tall again and this could happen within a 3 week span making the diagnosis from endoscopy with biopsy more equivocal.