How do I get rid of the sewer smell in our bathroom sink? It is not when the water is turned on, it looks like it is further down in the sink pipes.

How do I get rid of the sewer smell in our bathroom sink? It is not when the water is turned on, it looks like it is further down in the sink pipes.
Your bathroom lav is probably missing a p trap (or the water is leaking out of the p-trap) that blocks off sewer smell from coming up the pipes. .