My mom went through this twice. There is more than one type of surgical "fix" for this problem. My mom's story is a horror story that I would prefer to not elaborate on here.
(It seems all my stories are long and drawn out)
Please, please do your homework and decide which procedure is in your best interest for your particular situation.
If your bladder has actually fallen, and they want to use the sling method, try to find a doc that will use your own body muscle tissues to create a sling. That's the best advise I can give you. Personally, after what my mother had to endure, I never want it done. If I absolutely must, then I want the best surgeon possible with the best track record of success. Not just any ob doc will work.
By the way, you should be advised that mesh implants are a perfect harbor for infections to develop, and very difficult to eliminate.