I have several problems with my toilet. It recently started having problems when flushing, water would fill the bowl, but not empty. Occasionally the water bubbles up in the bowl indicating air problems. It does seem to be leaking on the floor around the bowl..but not all of the time. Ran a 15 ft. snake, no problems. Checked for any clogs, none that we can see in the house. Please help. Any advice will be appreciated. Thanks.