10 weeks post op Lipo and Brazilian butt lift, my stomach is still not flat. Any suggestions?

In the next two weeks is not much you can do about the result. There will be improvement but at this point time the changes will be slow. A pressure garment may give modest improvement.

The best 2 options for you at this point are: 1. body shaper and 2. lose some more weight. Since the swelling probably won't go down enough to give you a flat tummy is the remaining 2 weeks, you might be able to lose just a few pounds so that you look great for the dress. I would stay away for using diuretics or other drugs to look better. Good luck!

It's hard to say without knowing more about your situation. Your result depends on what your pre-op state was and of course the liposuction that was carried out. Edema or swelling after liposuction is very common, and usually patients don't see significant results until ~6 weeks after the procedure but there are changes all the way to 6 months or longer. At this point, only your PS will know if your expectation of a "flat" stomach is realistic. A stronger body shaper or corset may help you look slimmer in your wedding dress, but at this point it is unlikely to make a permanent difference in your actual body size.