Are you sure its "flab" and not just loose skin. Some people genetically speaking don't have very elastic skin and unfortunately have loose flabby skin after childbirth. I'm one of those people. I agree do some serious stomach exercises. Any "core" exercises with a workout ball, and Pilates are great for getting your stomach and waistline back. A simple 20-minute daily workout is all I do, and my stomach muscles are great..my waistline is back..but I have a small "flap" of skin near my c-section scar. I hate it and the stretch marks that seem to be deepest near the flap, but have been told the only remedy is a "mini" tummy tuck to tighten/remove the extra skin. For now, I have been checking out non-surgical alternatives. There are a couple of certified plastic surgeons in the area that do this, but its fairly new. I'm reasearching all I can. But I've also been told to wait until I'm sure I"m done having kids. So for now, I just wear pants etc. that hide it. Good luck. If you find anything else that works, do share!