Coeliac Disease is an autoimmune disease. When someone with coeliac eats gluten (a protein found in wheat,barley and rye) they can feel sick, vomit or get bloated. When they eat gluten their immune system attacks the small intestine and the villi (small finger-like things that help absorb nutrients).
Sudden/unexpected weight loss
Iron/vitamin B12/folic acid deficiency
For more information you can visit the Coeliac UK website.