my bathroom is fairly small, it is upstairs, has a shower in the far corner then a toilet and finnaly the sink near the door. problem started a few dasya go with the toilet getting clogged, i tried plunging as usual and dint work, i tried harder and noticed air/sound coming in from the shower drain, eventually toilet water came out. if i recall we ran a snake in the toilet drain and replaced the wax and is now running fine, the sink was never clogged, but if we used enough water and flush the toilet then water will come up from the shower drain. so we tried to snake through the sink drain, and cleared it out, but we have the same issue so im assuming the problem lies between the toilet and the shower, i believe the shower conenects to the toilet and then to the sink, which is why the ink doesnt have any issues, the snake we bought doesnt fit through the drain in the shower. what do i need to do to get this back up and running? thank you very much.