VSG to RYN due to acid problems
I revised from VSG to RNY in July, 2016 because of severe GERD. I did not have to wait 6 months for approval. My revision was approved the day after the request was submitted. But, I agree with others that it will depend solely on the requirements of your insurance carrier.
If you have specific questions for me regarding my experience with revision, I'd be happy to answer.