Nonresponsive celiac disease:
Some people with celiac disease don’t respond to what they consider to be a gluten-free diet. Nonresponsive celiac disease is often due to contamination of the diet with gluten. Working with a dietitian can help you learn how to avoid all gluten.

People with nonresponsive celiac disease might have:

• Bacteria in the small intestine (bacterial overgrowth)
• Microscopic colitis
• Poor pancreas function (pancreatic insufficiency)
• Irritable bowel syndrome
• Difficulty digesting sugar found in dairy products (lactose), table sugar (sucrose), or a type of sugar found in honey and fruits (fructose)
• Refractory celiac disease (In rare instances, the intestinal injury of celiac disease doesn’t respond to a strict gluten-free diet.)

https://www.mayoclinic.org/diseases-conditions/celiac-disease/symptoms-causes/syc-20352220