Gluten is a protein substance found in many cereal grains, such as rye, barley, and wheat. Many people cannot eat foods containing this protein because it irritates their digestive system. For most of these people, this is due to a medical condition known as celiac disease.
Celiac disease is an autoimmune disorder that is triggered when you eat foods containing gluten. When people with this condition consume gluten, the immune system attacks the small intestine and causes severe damage to its lining. It often causes symptoms like  diarrhea, abdominal pain, indigestion, bloating, heartburn, nausea, and fatigue.
Consuming even small amounts of gluten when you have celiac disease can cause damage to the small intestine, even if you do not experience symptoms .
There is currently no cure for this disorder. Doctors often try to manage it through a variety of therapies, the most important of which is dietary modification. For people with this disease, avoiding foods containing gluten is critical.
Here are some foods to avoid if you have celiac disease:
Cereal grains contain gluten naturally and are the main source of gluten. Doctors usually recommend that people with celiac disease avoid both grains containing gluten and foods made from them. Grains containing  gluten are barley, rye, farina, durum, emmer, khorasan, spelt, triticale, dinkel, einkorn, semolina, graham, wheat germ, wheat, wheat bran, wheat berries, farro, couscous, kamut.