Without an exam or pictures, it is difficult to tell you much. My guess would be that liposuction (if the pooch is fat) or a full or mini tummy tuck (if there is separation of the stomach muscles) should take care of it for you.
After gyn surgery the low abdominal incision may leave a shelf above the incision and accentuate any fat below the incision. In most cases, the best option is a tummy tuck / abdominoplasty to remove any redundant or loose skin and also to tighten the underlying muscles. Without seeing you in person, it is impossible to give you specific advice for your situation. A consultation is the best recommendation.Good Luck
These areas that after created after a hysterectomy can be well treated with a tummy tuck, which addresses the skin excess fat and muscle weakness of the abdomen.