Venting in Bathroom Wall

[boardcertified]

We just experienced a flood out in our home over the Christmas/New Year's holiday and the culprit was a leak in the main bathroom/laundry room wall where the plumbing supplies both the bathroom and the laundry room. The leak was found at the point where a compression fitting had two holes in them the size of toothpicks. We realized that the leak created an even bigger problem since 'everything' through the master bath, main bath, laundry room and family experience some degree of severe wetness. You can imaging the job of restoration that was about to take place. This all started on 12/19/14 and we finally moved back in on 2/27/15. Almost 3 months after the floodout. Everything looks great!
The question I have is about venting in the master bathroom. The sink 'slowly' drains and I was told that it could be the lack of venting in the wall. Is there any way that I can add venting to correct the problem without going through the new remodel.
Appreciate your thoughts and comments.

[Greg]

Many sinks use a check valve type vent under the counter, If you have one they have been known to go bad. I really can't see a restoration company removing a vent.

Greg

[boardcertified]

Greg,

I contacted the plumber and he assured me there was a vent in the wall. He corrected the problem by taking the black 'O" ring out of the stopper and we are good to go. Easy solve.
One of those free plumber tips. All is well!