Bathroom Sink Gurgling

[starrs]

Whenever we have trouble with a gurgling sound in our bathroom sink the problem is usually resolved by removing leaves etc from the drain outside. Yesterday however the noise continued so I used a drain unblocker from B&Q. This released a little bit of debris but the gurgling continued. So I unscrewed the trap under the sink and there was some hair stuck to the pipe but when the trap was replaced the gurgling continues. Is the problem trapped air and if so how do I overcome it.

Thanks for any help.

[starrs]

Sorry, forgot to say that the water seems to be draining away ok, it's just the gurgling sound causing the problem. Thanks.

[wolf63]

I don't understand DIY and plumbing. But sometimes when my bathroom sink gurgles it is actually the bath that is blocked up.

[AlBags]

Clean out right to the bottom of the inlet gully outside.