"Rebel1" wrote in message ...
The toilet has been off the closet flange for a week, and I have not put
anything in the drain pipe to prevent sewer gases from drifting up into
the bathroom. Yet I don't smell any, and my smelling is excellent. From
the plumbing diagrams on the web, there are no traps other than the one
in the toilet. Should I be concerned that there is a blockage further
down the drain?

The house is 15 years old and built on a slab.

The gases are probably seeping out into the room and you don't notice them. Try covering up the drain for a day and then removing and see what it smells like.