I don't blame you if you don't believe this. If I hadn't seen it
personally, I wouldn't either. Here's the situation.
After 10 years, the caulking around the base of the toilet and the tile
floor it sits on started look shabby. So I removed it. Before replacing
it, I took a shower. After getting out of the shower, I noticed that the
rug in front of the toilet was wet. I thought that maybe one of the two
sliding shower doors wasn't fully closed. So I just wiped the floor dry.
Next day, still with no caulk around the base of the toilet, I showered
again. Now I could see water oozing out from around the toilet base. The
shower nozzle is at the end of a 6' hose, so while standing in front of
the toilet I aimed the nozzle directly into the shower drain (about 32
inches away), hoping to see water seep out from the toilet base. That
Next, I removed the toilet and again aimed the nozzle directly into the
shower drain, for longer than it takes me to shower. By listening at the
toilet drain, I could hear the water running out the shower drain, but
no water was visible at the toilet drain.
There is no sluggishness in the shower drain or when the toilet flushes,
so I have to rule out a partial blockage past the point both drains
merge. Since the house is on a slab, and I only weight 145 pounds, I
can't attribute the oozing due to floor deflection when I'm standing in
the shower. And there's no seepage when I flush the toilet.
It would appear that the old caulk was damming back the water, but there
was no caulk at the back of the toilet because it was too hard to reach
that spot. So any dammed water could have escaped at the back.
The old wax ring was still soft and sticky, but there was some black
discoloration (maybe mold) at one point. There may have also been a
passageway between the inner and outer diameters at this point.
I installed a new wax ring and that was the end of the problem (still
with no new caulk). But I can't figure out where the water came from,
even if there had be no old wax ring at all.
Possibly there's a tiny leak in the bowl itself, but I don't see
evidence, either from leakage around the base or from a lowering of the
water level after a few hours of disuse.
Intriguing problem. And ideas? Maybe something bizarre with air pressure
in the vent to the roof.