Stomach Bulge After Tummy Tuck and Liposuction

Libra,
It is much too soon following your surgery to be critical of your results. It may take a full 6 months for all of the swelling to subside and the tissues to contract to their new contour.  So, hang in there, be patient and follow up with your plastic surgeon. Good luck!

It is difficult to assess why you would have a persistent roll when sitting after tummy tuck and extensive liposuction, It may be: 1) conservative skin removal, 2) need for more liposuction, 3) recurrent skin laxity, 4) excessive liposuction with skin laxity, 4) retraction of SFS repair with tethering of scar to rectus fascia and resulting shelf like deformity, 5) a low umbilical inset with gathering of tissues beneath this area 6) short waist with costal margin impinging on iliac crest, etc

Hi there-
The situation you describe is quite common and is not necessarily indicative of a problem. If your abdomen is flat when you are standing, and you have a pleasing contour, but you see some fullness when you sit, this is more likely an indicator that your skin has simply lost some elasticity (which you already knew, and is no doubt one of the reasons you were having a tummy tuck).
When a young person, with excellent skin elasticity sits down, the skin contracts (because it is elastic), but if the skin has lost some of this quality through pregnancy or weight gain and weight loss cycles, it will not be capable of this contraction in the sitting position, and the skin will appear a bit redundant. It's really a skin QUALITY issue, not a skin quantity issue. I would visit with my plastic surgeon to make sure something else isn't going on, but it sounds like you have a very nice result. Congratulations on your new contour!