Celiac disease is a digestive disorder caused by an abnormal immune reaction to gluten. Celiac disease is also known as:sprue nontropical spruegluten-sensitive enteropathy Gluten is a protein found in foods made with wheat, barley, rye, and triticale. It is also found in oats that have been made in processing plants that handle other grains. Gluten can even be found in some medicines, vitamins, and lipsticks. Gluten intolerance, also known as gluten-related disorders, is characterized by symptoms after eating gluten containing foods. People with non-celiac gluten sensitivity may have a mild sensitivity to gluten, while others have celiac disease which is an autoimmune