How Do I Fix a Bad Belly Button Scar After Tummy Tuck?

Unfortunately, it appears that you are going to have a hypertrophic or keloid scar, regardless of whether your surgeon used external or internal sutures.  Most people do not know this, but it is actualy better to use the external stitches on people you worry about heavy scarring, since once they are out they cannot have a reaction to them anymore.  The internal stitches stay for 3-4 months, and your body is reacting to them the entire time, building up scar tissue.  I would try the steroid injections first, thena revision with steroids at the same time, followed by some silicone sheeting during the healing process.  95% of how you heal is just your genetics, and there is often very little that we as surgeons can do to alter that.  I hpe this helps.

Abdominoplasty scars can be quite complex, ranging from the simple hypertrophic scar to a multiplane inflamed keloid. Pigmentation, discoloration, chronic inflammation, scar visibility can all occur in the short term. We begin each treatment with combination therapy using Yellow broadband BBL, Vbeam, fractional erbium, intralesional IIT, and scar modulation. Start with a combination of Plato's Scar Serum massaged twice daily after one week of epithelialization followed by Luminase/Exfolase. Scar consultation and revision may be recommended.

Best,
Dr. Karamanoukian
Realself100 Surgeon6

As I have said in the past,  the scar is 50% the surgeon's skill and 50% your response to his/her injury. Irregardless of technique, bad scars can result and cannot be entirely preventable.