The following cereals should be avoided in patients with celiac diseases, except –
Celiac disease (celiac sprue/gluten-sensitive enteropathy) 

Celiac disease is a chronic disease, in which there is a characteristic mucosal lesion of the small intestine and impaired nutrient absorption, which improves on withdrawl of wheat gliadins and related grains proteins from the diet.
The fundamental disorder in celiac sprue is sensitivity to gluten which is alcohol soluble, water insoluble protein component. It is found in wheat and closely related grains such as oat, barely and rye.
Celiac disease presents with features of malabsorption and the characteristic is that withdrawal of gluten containing substances from the diet i.e. (wheat, oat, barely and rye) produces dramatic improvement in the disease.
Wheat
Barely
Maize
Rye