We just bought a house and the guest bathroom has an awful smell coming from the toilet, how can we figure this out?
When I bought my home I had a similar problem and I found out that the wax seal at the bottom of the toilet had deteriorated. When I replaced it and cleaned up the goo around the bottom of the toilet then the problem disappeared. But the above answer can also pose the same problem but once it has been eliminated I would also check for the wax seal at the bottom of the toilet.