Hope you can help. Recently I have noticed that the toilet bowl water (not the tank) in the master bathroom on the second floor is extremely low. Last weekend I went to clean the toilet in the guest bathroom, also on the second floor, and the bowl was empty, dry! There are no signs of a leak anywhere, although I sometimes hear dripping in the kitchen ceiling. A few months ago I had a plumber come out to investigate the dripping but he couldn't hear or find anything. Do I have a leak somewhere?

First question would be -- do you have cats or dogs?
Second one is did your house ever get below freezing this winter? -
The standing water in a bowl is trapped as far as I know so a pet , a crack below water level or evaporation is the only 3 picks out there that I know of. - Savage