Vagina swelling after lipo? How can I stop this or soothe the swelling?

Sounds as a gravity effect after lipo in the lower abdomen. BEST to see your surgeon as needed to fully explain this to you... 

It is common for labia in women and the scrotum in males to become bruised, black and blue, after a tummy tuck. The simple explanation is that even a few drops of deep blood move down fascial planes with gravity and lymphatic flow to this area. It will resolve in most cases rather promptly. Check with your plastic surgeon to make sure this is the case with you.#tt#tummytuck

I understand your concerns but you are experiencing what sounds like normal postoperative swelling after liposuction of abdominal region. Seek follow up from your surgeon.