Abdominal seroma pain with fullness and distention. What's the best treatment?

If you are having enough abdominal fullness to cause discomfort, you should return to your surgeon as soon as possible. Early treatment of seromas with percutaneous needle aspiration is usually effective. Delaying treatment may lead to a need for drain placement or even open more aggressive options. 

I would recommend that you return to your plastic surgeon soon.  Percutaneous drainage of your seroma might be warranted in this case.

Seromas occur when fluid is trapped beneath the skin. it is best to treat them promtly to reduce the chance of infection and chronic fluid accumulation. You should return to your surgeon as soon as possible.