I'll try to keep this brief. About a week ago we noticed that at times, the toilet wasn't flushing like it usually does. About every third flush or so the bowl would fill up and we'd have to plunge it down. (city sewer, NOT septic tank) I have a 3 yr. old and a 5 yr old, so I figured they had flushed something they shouldn't have... So Yesterday I removed the toilet and took it outside to check it out. Nothing came out of it that I saw while 'flushing' it out. I set it up on some milk crates and filled the tank 20 times and then flushed...... everything was working as it should. I re-installed it with a new wax ring, and for the first 5-6 flushes everything was great! Now we are back to plunging it again...... Could I have a vent problem or something? We are tiring of plunging, and can't afford to have a plumber take a look at this time..