I have a saggy butt after liposuction, what can I do to fix it? (Photos)

it seems like the liposuction performed on your affected side was a wee bit more aggressive than the other side. I will have to see you in person to be able to better help you but it can certainly be improved upon. I can't say i can bring it back 100% to normal but it can be made better for sure. 

Our Hidef Liposuction protocol addresses skin tightness and laxity, contour irregularities, and body proportions to reestablish harmony in the body. Options include fat cavitation, fibrous release, RF multiplane tissue tightening, fat grafting, fat matrix, liposculpture, and liposuction. Cellulite can also be addressed with our exclusive Brazilian Cellulite Treatment. 
Best, 
Dr. Karamanoukian
Realself100 Surgeon

Dear saggysaggy,
I would recommend that you consider Radio frequency assisted liposuction to the lower buttock and proximal thigh areas.  The radio frequency technique heats the tissues;  this will result in significant skin tightening of the treated area- which is what needs to be done.  I would not recommend any significant additional liposuction.  How far post-op are you from your last procedure?  I would wait a minimum of 6 months before any additional treatment.  In th U S RFAL is available under the name "Bodytite".  Hope this helps.
James Sheridan, MD
Austin, TX

In order to correct sagging you will have to consider liposuction of the lower back and flanks and lateral thighs with VASER technology and transfer to the buttocks.