I'm trying to troubleshoot a problem in one of my bathrooms, where water is leaking from around the base of the toilet, and the shower is backing up and overflowing after running for about ten minutes. At first I only noticed the toilet problem, and thought it might be the wax seal. I replaced the seal, and now it doesn't leak as bad (or at all if no one has taken a shower), but if I flush it within 20 minutes of a shower or so, it will still let some water out around the base.

We have a second bathroom in the house, and it is fine. And I'm not smelling any septic gas smell, so I don't think it's our tank (which was emptied not long ago anyway).

I'm wondering if it's possible there is a clog in the pipe that is far enough down that the toilet/shower meet, but before it meets the main line that services our other bathroom? What would the best way to fix that be? I tried snaking the toilet early on, but just with a little 5' snake. Do I need to get a 25' drum auger and try to clear it that way?

Any tips would be most appreciated!