Tummy Still Bulges After Umbilical Hernia Repair

After the birth of my son 4 years ago (delivered by c-section) I was told during my pregnancy my baby had torn my stomach muscles in two. I was advised I had a ventral hernia but had to decide if we were going to have more children before having it repaired. I recently saw a different Dr who advised of umbilical hernia & carried out a repair. I still have a very 'bulbous' stomach, and wonder if I need further surgery? Will exercise sort it? I get very unhappy with my tummy.