My bathroom has 3 fixtures in it (sink, tub, toilet). After running the water for a few minutes, the toilet starts to bubble and the tub gurgles. The drain then begins to slow down. The toilet won't flush for about an hour, and then everything seems fine. This used to happen about once a month, but now happens almost constantly. I'm going to gut the bathroom in a few months so I don't want to get too involved with it if I don't have to. Any help is greatly appreciated.