On Oct 20, 10:54 am, wrote:
Hello,

I have an older toilet. A few years ago, I
changed all the parts inside the tank. It
has worked fine since then. Until now.

Lately, it has an odd pattern. I flush the
toilet. The tank and bowl refill fine.
I've watched them.

Then I come back next time. And the bowl is
almost empty!

And, it only seems to happen intermittently.

It's really bizarre.

Does anyone have any idea what might be
causing this, and the solution?

I don't know what you mean by "older toilet" but if
it's anything like the conventional home toilet, you
obviously have a leaking rubber stopper. The refill
valve/float assembly is also very likely in need of
replacement since it does not respond to the drop
in water level as the water seeps out.

You can get all this stuff for under $10 probably
and install it yourself.