Our bathroom smells like urien - I had the sink drain removed and cleaned, put bleach in tub drain, toilet does not appear to be leaking at the base, floor is not carpet... I have cleaned and cleaned with bleach... even checked in basement below bathroom to see if any signs of leaking... Just beside myself as to what would be causing this awful smell... can hardly stand to go in the room... HELP!

If you have a lot of men in the house, maybe male children, husband, whatever, probably urinating in their sleep and its running down the toilet onto the floor and drying.. . mmm, only thing I can think of

Check between the tank and the bowl. There is a space there and maybe an "overshoot", or many has allowed urea to collect there.