Although losing a ring in the toilet isn't as common as losing one in a sink drain, it's more difficult to prevent. You can protect a sink drain by putting in the stopper or a rapid fit drain covering when you use the sink, but a toilet is always uncovered when you're using it. When you do drop something small and heavy, such as a ring, down the toilet, it's easy to retrieve before you flush, but after you flush, there's a good chance that you've lost it altogether.
I Flushed My Ring Down the Toilet
Relatively heavy items like rings are likely to settle in the bottom of a sink P-trap, and you can get them back by disassembling the P-trap. That's not true for a P-trap toilet seal because toilets actually generate suction when they're flushed. So, if a family member or guest comes to you and says, "I flushed my ring down the toilet," keep a positive attitude and hope for a miracle. After removing the toilet, you may find the ring lodged inside the P-trap or stuck in the waste opening.
If you drop something valuable in the toilet, don't flush. The item will settle in the bottom of the P-trap toilet seal, and you should be able to fish it out with a piece of wire. It might not be a pleasant experience, but at least you'll get the ring back. If the ring is gold or silver plated, you may even be able to get it with a telescoping magnetic retriever.
If you flush, the ring will probably go down the drain, but it depends on the force of the flush. A toilet usually generates considerable suction – definitely enough to pull a ring out of the bottom – but if the toilet is old and flushes slowly, you may be in luck. You may find the ring at the bottom of the toilet seal P-trap after flushing is complete. It's a long shot, but it's definitely worth checking.
Remove the Toilet
No sign of the ring after flushing? It might be lodged inside the toilet or in the waste opening, but you'll have to put on rubber gloves and remove the toilet to look. Shut off the water and drain all the water out of the tank and the P-trap toilet seal. The best way to drain water is to suck it out with a turkey baster, but you can also use a sponge.
Using a wrench, loosen the bolts holding the toilet to the floor, then lift the toilet and set it on the bathroom floor. Tip it on its side so you can look inside the waste opening. Check the wax ring, part of which is stuck to the bottom of the toilet and part to the flange, which is the waste fitting to which the toilet was attached. You should also look inside the waste opening with a flashlight. The ring may have gotten hung up in there for some reason.
Call for Help
Many plumbers are used to calls from people who flush wedding rings and other valuables, and they have a camera or scope that allows them to inspect inside drain pipes. You can also rent one of these yourself. The chances of finding something small and heavy like a ring before it drops into the sewer aren't huge, but they're not negligible. If scoping the drain leaves you empty-handed, you have one more option, assuming the ring is valuable enough. Contact the water department of the city or municipality in which you live and ask to have the sewer inspected through drain openings on the street.