What would cause this pocket of fat in lower back? (Photo)

This could be swelling from the surgery.  It is possible that you have had fat in this area prior to your surgery and that it has been accentuated by your procedure, which may have included liposuction of your flanks, but not this region.  Please see your surgeon who can best advise you.

It is very common to have a fat pocket in that area of the lower back.  More likely than not, you've had this all along but you just didn't notice it pre-op.  It may also be possible that the fat pocket looks more prominent now because of the post-op swelling after your surgeries.  Continue to follow up with your surgeon and take care!

It is quite possible that this is simply a result of your toro being swollen post surgery. Give your body a couple more months to heal and then reassess with your surgeon. Best, Dr. Nazarian

If this is fat, it was there before your recent surgery. Honest. Your awareness may have just started after having had your surgery, but it did not "grow there" in 2 weeks.  However, if this is truly a new bulge that definitely was not there before, it is simply fluid that has collected within these tissues via gravity. If this is the cause of the bulge, you need do nothing--it will reabsorb on its own over the next few weeks,If, on the other hand, this indeed was actually there long-term and was just now discovered by you, it will require liposuction to remove.I'd wait for a few weeks and take another photo, then compare. Best wishes!

This may not be fat at all, but instead be swelling related to your healing. Visit with your surgeon to make sure your compression garment is fitting properly and discuss your activity level to ensure healing is going appropriately.

This could be due to swelling in your truncal region and with time it should subside.  Surgery did not cause you to develop new fat in this area.  Continue to follow up with your PS.

Thanks for your question and pictures.  You are very early still after your surgical procedure.  At this point you likely have some minor swelling that will slowly decrease over the coming months.  This could also be a small amount of fat that was not removed during your liposuction.  Don't worry, new fat hasn't grown there; it just may be more apparent after surrounding fat was removed. Give it a few months, keep in touch with your plastic surgeon and consider (if needed) additional liposuction in about 6 months.  Cheers and best wishes!Steven Camp MD#HappyCamperMD