Our upstairs bathroom has a terrible smell that seems to be coming from the toilet. We do not have this problem with our other bathroom. It smells like something rotten and the smell comes and goes. My husband took the toilet apart, replaced the wax ring, cleaned around the toilet & cleaned the tank. The shower drain and sink drain are fine. He cleaned out the vent on the roof as well. The smell is STILL here! Nothing seems to work. What could cause this smell?

Does the toilet bubble when the tub's draining?

The water in the toilet bowl moves slightly, but no bubbleswhen the tub drains.