Belly Button Revision after hernia repair
An examination would be required for the best opinion especially as one of your photos shows bulging around the belly button which could mean either a hernia or else abdominal wall laxity which may have to be corrected for the best appearance. The bottom line is that surgery including an umbilicoplasty should be able to improve your appearance.
Umbilicoplasty after abdominal surgery
Based on the pictures you've posted, it appears that you could benefit from an umbilicoplasty to improve the appearance and reduce the "bulging" of the skin in the umbilicus. Make sure to find a Board certified plastic surgeon--the ASPS website has a useful physician referral tool to find qualified surgeons in your area.