What can cause the smell of human feces to a minute from a pristine toilet?

You may want to check if there is a leak in your sewage line. That is most likely the cause for that smell. Check the piping to make sure, because the smell will only get worse if it is not taken care of immediately.

Hi Faith

I would guess that the wax seal under the toilet may have been set improperly or has worn down. Here, if the wax seal failed it could allow sewer gasses to escape into the home. The only way to fix this issue is to lift the toilet and install a new wax gasket.

Back to you...

Mark

Are you certain it is coming from the toilet and not the shower or tyb drain?

Please respond to the experts questions, Thanks.

John