Bathroom odors coming from toilet-to-floor gasket seal?

I had a mystery deal with my toilet. Turned out the flange was not sealed properly/totally to the down pipe. Some silicone took care of that.

Redoing the flange gasket is a piece of cake (once you get past the smell :R ). As I recall there are different thicknesses, so if your situation permits, it my save some some time and running to yank the toilet first. Course if your supplier has two thicknesses, you could buy the both and later return the one not used.