I am in a modern condomiunim. My unit is next to the laundry room (wondering if that's relevant due to the washers). Occasionally, the toilet gets air bubbles for about a minute. If I try to flush during this period, the toilet just overflows and the water doesn't empty. I tried using a plunger to force the water down, but no luck during one of these episodes.

Occasionally, at other times, if the toilet is just sitting there, air bubbles will start bubbling up (LARGE ones too). Also, the toilet sometimes just empties by itself and then refills (presumably from the stuff that "emptied" and I get a really FOUL smell in the room afterwards a couple of hours later. Please help!