coeliac blood test

Hi
My doctor had my blood tested for Coeliac disease as I was displaying a lot of the symptoms.
When I saw him for the results, he said that I ‘more than likely’ am
Coeliac. He didn’t recommend me doing the internal invasive test as my results confirmed our suspicions. He then told me to eliminate all wheat from my diet, but told me oats and barley are ok?
Now I’m confused. Oats and barley contain gluten so why has he told me I can eat them?