Hi there:

How can I easily chek if my drainage vent is plugged? I just bought a new home and the downstrairs bathroom smells but not everyday. I am going to try the bleach trick tonight but the house is brand new I wonder how I could have hair in the sink.

Where's the smell thr worst? Drain? Toilet? When a vent's blocked you will hear gurgling in one or more bathroom traps. Good luck, Tom

It may be as simple as a poorly installed wax ring on the toilet. Tom is 100% correct about plugged vents causing gurgling.