I have two bathrooms in this house. We just bought it and moved in... for about a week everything worked perfectly. Then about 4-5 days ago we noticed the toilets started bubbling when one of us was taking a shower. I didn't think much of it. Well about 2 days after that the shower decided it didn't want to drain (well it does drain just at a very slow rate). Once the shower stopped draining it also stopped the toilets from flushing. They would just fill to the top and then about 2 hours later they would be back at the proper level (same as tub). As long as no one is showering the toilets work fine. One thing I find strange is that when the shower and toilet is backed up I can run the sink in the same bathroom and it runs / drains just fine. I have read many posts about how this could be a vent line problem or a main line clog problem (but if main line I'm curious why the sink doesn't back up). Any other light someone can shine on this about which of these they think the problem is and what steps I should do to address it? Thanks a lot in advance.

Sounds more like a vent problem and not the main drain , yet. Rod from the roof if safe, use enough snake to reach roof top to basement floor plus 20' The bubbles are your toilet trying to acts as a vent for the shower

Are you on a septic system or public sewer? It sounds like a septic problem.

Bubbles indicate a partial blockage while gurgles indicate a blocked vent.
Follow Bobs advice and snake the vent first. If that don't get it click on b ack and tell me about it.
Is this a stand up shower on a tub? Let me know, Tom

Bubbles indicate a partial blockage while gurgles indicate a blocked vent.
Follow Bobs advice and snake the vent first. If that don't get it click on b ack and tell me about it.
Is this a stand up shower on a tub? Let me know, Tom

Thanks guys for the help.

It is public sewer system not septic tank.

The tub is a tub not a stand-in shower.

The toilets are bubbling.

Now a new problem I found today. When washing the dishes my wife tells me the toilets are bubbling. I go into the bathroom and the tub is filling with water from the drain as I run the water in the kitchen sink. Now it's sounding more and more like a blockage since the water seems to be backwashing into other parts. Is this just my water not draining hence it is backwashing into open drains or do I have any risk of sewage or something backwashing into my house?

Any ideas? Thanks.

This is , indeed, a blockage. The blockage will be downstream from the tub.
You can get at this several ways.
1) Snake from the lavatory roof drain, Put out enough to reach the base and 20 feet more. **OR**
2) Remove the overflow plate and send a snake down the over flow, (see image) You will hit the return bend of the trap but once around that you should have less then 20 more feet to put out. Good luck, Tom

Thanks speedball. I think I'll try the snake in the overflow before I call a plumber. Money is kind of tight and I'm not sure what it will cost to have a plumber come out and fix this (please post if you have some idea of price). I've never done this before, but it doesn't sound too difficult.

Ugh. Ok about 2 feet in I hit a snag which I guess is the return bend. Then after I move passed that I get about 2 more feet in and the snake doesn't want to go anymore. Any ideas?