Any nasal surgery might have drainage that has an unpleasant odor, e.g. old blood. Have you tried rinsing your mouth with anything, e.g. salt water, listerine, etc... and drinking lots of water may help as well. If the doctor gave you an antibiotic, you may have a little infection. If nothing helps it by the time the antibiotic is gone (and always finish those Rx), get back to your doctor.
Hi there,
It is common to have some discomfort after surgery. A follow up visit is important after any surgery. In this visit the doctor will clean and examine the operative site. It is possible that there was packing left in your nose which is causing bad taste in mouth and nose. This is merely an advice and not a substitute for clinical examination. For more queries and assistance visit an ENT specialist. I hope it helps.
Best luck ad regards!