Already on a gluten free diet or unwilling to undergo a gluten challenge

Undergoing upper endoscopy for an urgent indication such as unstable gastrointestinal bleed or food impaction

Patients with inflammatory bowel disease

Patients on blood thinners other than aspirin at time of endoscopy

Patient unable to give informed consent

Patient less than 18 years old

Assessment of Duodenal Epithelial Integrity in Celiac Disease With Mucosal Impedance