How would vagal nerve damage be treated and diagnosed. i believe i have issues and thus far prednisone is the only thing that helps.

Look for new answer: The vagus nerve carries sensory information from the abdominal organs including the intestines and some motor ( muscle)) function. If you are having problems relieved by Prednisone it is more likely you have an inflammatory process invving the abdomen and/ or intestine. It would be unusual to have a Prednisone responsive problem affecting only the vagus n. And not the brain or other cranial nerv.