Just bought my house and the toilet overflows frequetly. Tried using a plunger but this does not help. Sometimes the waste is removed but then the toilet will overflow anyway and the water then drains very slowly. Also, the tub will not drain and will back up with dirty water if both the toilet and shower are used near the same time. Finally if I dump the water from the over flowing toilet into my bathroom sink, the toilet makes a gurgling sound each time I pour a cup of the toilet water into the sink. Any help is greatly appreciated.

That sink, toilet and tub all come together into one drain line which is clogged. Skip any polunging or rodding on the toilet. Go down the tub overflow plate after removing it or go into the wall after removing the sink trap, use no chemicals.