The drain in my bathroom smells everytime I use the faucet. How do I get rid of this?

The drain in my bathroom sink smells like rotten eggs every time I use the faucet in my bathroom. It's not clogged and the water flows down the drain fine. I've tried pouring some bleach down the drain to try and get rid of the smell but it still stinks. It's the only drain in our house that smells like that. Any ideas on how to get rid of this smell?