Does anyone know if it is possible for separated stomach muscles to come together again?

I have had four children and my stomach muscles separated with the first pregnancy. Looking back I probably didn't have very strong stomach muscles to begin with and I tended to carry very "up front" and had big babies. Despite working on my abdominal muscles over a period of time (approx. 10 months), I don't think it has made any difference in the separation. When my stomach is tensed I can almost fit two fingers between those hard muscles. I think this is one of the factors contributing to my "pot" belly along with the layer of fat, or course

TrainerDan, Fern, anyone want to tackle this?