We changed the wax ring on our toilet due to a small water leak. A bad smell now comes from the bottom of the toilet, mostly at night. Called the plumber. He replaced the ring again. Still the smell. We caulked around the toilet. The smell was almost gone for a week but now it is back as bad as ever. When we replaced the ring the first time, we found they had previously used two wax rings.

They used 2 wax rings because the Closet Ring was set too low below the finished floor.

You should install extension rings. Use as many as needed to bring the Closet Ring even with the floor. Then, you can use only one wax ring.

When setting toilet, make sure toilet sits on top of the wax ring and squeeze it as it is pushed down towards the floor. If the toilet goes down too easily, than you need another wax ring.

Oh my gosh... are you still having this problem? I am too and am at my wit's end!! Did you get this solved?