Have you had a nasal swab done yet? My nasal discharge had a very unpleasant smell years back, I was swabbed and tested positive for a neurotoxic staph infection, the treatment for which was topical application of an ointment called 'Bactroban'. I used this for a while but found that I had to avoid most complex carbs before the problem started to ease. I still have a slightly yellowish discharge if I don't religiously restrict my complex carbohydrates.Tony.