My housemate described the following situation to me:
She went to get into the shower tonight and saw that there was crud in
the bathtub, like something had forced dirty water up through the
drain. She also noticed that the water level in the toilet was lower
than expected. She rinsed down the tub and took a shower and while she
was doing so, she could hear the toilet gurgling and saw bubbles
coming up through the toilet water.
Coincidentally, I was in the basement, underneath all of this, and
happened to see a little bit of water leaking from the PVC at the
joint above the p-trap. When I got upstairs, she explained what she
experienced. She then went to flush the toilet and the water level
raised to a full bowl but didn't drain.
We plunged, and eventually the water drained to an empty bowl, but it
wasn't a sudden flow like moving a large clog. I went back into the
basement and tightened the joint above the tub's p-trap and also
noticed a tiny bit of water had leaked out of the big pipe under the
toilet. The joint is too far into the floor for me to see for certain
where it came from.
Does anyone have an idea of what could be happening here? I'm often a
do-it-yourselfer, but this one stumps me and I am thinking of calling
a plumber. Any ideas people have would be helpful. Let me know if you
have any questions.
Thanks!
Adam