Sorry, but I think that doc is full of crap.
http://www.fitstep.com/Advanced/Anatomy/Abs.htm shows how the abs are put together, during pregnancy they seperate and allow the uterus to come forward and up. Unless you've had some sort of abdominal injury which prevented that from happening, I can't see how the muscles are that stretched out. I have a huge lower belly, most of its fat, some of its scar tissue, but under all of that is muscle. Lay on your back, feel around until you can find the actual muscles, sometimes, I have to start under my ribs to find it and follow it, then follow the muscle until you reach your hip.
The best thing you can do, is to keep training those muscles, just like every other muscle, while consistently losing weight. Other than surgery there is no magic machine to get rid of just that one are. On me, it'll be the last to go, but it IS going. I've had OB specialists and surgeons at UCLA look at my abs due to a cellulitis infection after my last c-section, I was hospitalized for 10 days, 3 of which was in the ICU, because the infection was completely out of control. It ate away fat cells, thankfully, no muscle which an MRI proved to be in good shape, after a twin pregnancy, followed by 2 more pregnancies all within 4 yrs of each other. I know everyone's different, but if mine are in good shape after 3 back to back pregnacies, and I've been told over n over, lose weight, then we'll see, I can't imagine why any doc would tell you the only way to get rid of it is with a tummy tuck, unless of course, he does tummy tucks. Also, did you have an MRI? IS that how he got the info? Just looking at someone's outer covering is not an adequate way to make that determination, UNLESS you have lost all the excess weight and it's still there. I'll still have a small pooch and fold of skin, which is fine, for now, as long as I know I'm as healthy as I can be.
If you are considering a tummy tuck, make sure to visit several surgeons.
I wanted to add this link that further explains seperated ab muscles during pregnancy and how to help them.
http://womenshealth.suite101.com/art...ominal_muscles