Proposed diagnostic algorithm for non-responsive celiac disease. 1. Dietary compliance should be assessed by an experienced dietitian to rule-out continued gluten exposure. 2. Consider colonoscopy with biopsies if symptoms clinically warrant. 3. To include testing for pancreatic insufficiency, small bowel bacterial overgrowth, lactose intolerance (based on clinical symptoms). EGD, esophagogastroduodenoscopy; RCD, refractory celiac disease; RCD1, refractory celiac disease type 1; RCD, refractory celiac disease type 2; GFD, gluten-free diet.