You will quickly find out that very few doctors other than cf clinic doctors know very much about CF at all. My son sees many specialists for things not related to CF and every single one of them looked at me like I had three heads when I told them he had been diagnosed with CF. I started taking the official letter from the CF clinic with me when I see other doctors now so they don't think I'm losing my mind. I think most doctors learned about CF 20 years ago in medical school and then never see it again. On the other thread you mentioned his sweat test may have been wrong because he was sick. Malnutrition is a cause for a false positive sweat test and there are some diseases that cause high sweat tests also (Celiac Disease, Hypothyroidism, Nephrogenic Diabetes Insipidus, etc). The CF clinic will probably run tests to rule out any of those causes also. I don't want to get your hopes up though because besides Celiac Disease the other diseases are fairly rare. I'm in the same boat you are. My son has been diagnosed with cf although his genetics came back with no mutations. It's a strange boat to be in.