RNY to DS is a very complicated surgery. There are very few qualified surgeons in the USA that will tackle that one. I have never heard of a surgeon that does that revision in Mexico.
I have heard of shoddy surgeons telling you that they are doing an RNY to DS revision, when in fact they are revising to a distal RNY and charging you for a more complicated DS revision. Distal RNY is not much different that your original RNY. The only difference is they bypass more of the intestines so your malabsorption is more severe. Many people become very vitamin deficient after distal RNY. Yearly labs and vitamin compliance become even more important. DS also requires vigilance with vitamins and labs. Either surgery can be eaten around and you can regain if you are not compliant with food choices.
Are you revising due to mechanical failure of your RNY?
I would do a ton of research and proceed with caution.
After much research and investigation and due to the complexity of this surgery I chose to stay in the US and am having my Rny to DS revision surgery on Feb 5th with Dr. Steven Simper from Rocky Mountain Bariatrics in SLC.
The surgeon basically has to "put you back to pre wls" and then perfom the DS it is extremely complicated. My advise is to do your research carefully and choose a surgeon you feel comfortable with and have complete confidence in no matter where you choose to have your surgery.