There is something that you can find on every pipe in your home that is connected to the sewers called a p-trap. The purpose of a p-trap is to keep sewer gasses from seeping into your home. Inside a p-trap there should always be enough standing water to block off any airflow through the drain. If there isn’t enough water in your p-trap, you will very quickly know that from the smell. This does happen in drains that aren’t used very often. To prevent this you could install a priming tap that will add water when it gets low.
Sewer gasses smell really bad, but apart from that, they can also have serious health effects, so it makes sense to keep them away.
Sometimes you will notice that there is a little drain plug on the p-trap. This will let you access anything that you might have dropped down the drain, as well as, give you a way to access it to clean it out. If it doesn’t have a drain, you would need to take the pipe apart to gain access.
