Do all doctors requires a liquid pre op diet before a VGS?

The request is for two mainly super important reasons: to reduce the size if the liver which gets very large due to the overweight, so it is extremely important the surgeon does not have a technical problem which may end up with a very serious complication. And the other important is because your hole large intestine should be empty to avoid being in an obstacle and reduce the risk of perforation. For those  reasons you must be in liquid diet several days before surgery. Just have in mind the deadly complications you may avoid just following instructions. Dr. Cardenas 

We use a 2 week liquid diet of protein shakes, protein soups, and a protein bar once per day. The fat deposits in the liver must go away so we can get up under there to your stomach. As an american surgeon, I have to question the allure for surgery in Mexico. You should seek a 2nd opinion from the surgeons at the Cleveland clinic since you live in south Florida. You need a perspective from surgeons who end up taking care of complications from surgeries out of the country.

I certainly require a one-week preop high protein liquid diet. This does two very important things to make the surgery safer. One, it empties out the colon so it is out-of-the-way and if it is injured during the procedure, which is exceedingly rare, it can be easily repaired without complication. Secondly it shrinks the liver. The area of the operation lies directly underneath the liver. Most patients have an enlarged fatty liver. This makes it difficult to retract out-of-the-way during the surgery. The liquid diet really does shrink down the liver and make the surgery easier on the surgeon and therefore safer for you. When you ask your surgeon this question in Mexico, a better question would be who would pay for complications of the surgery should they occur. The best surgeons in the US have complication insurance that is included in the price of the cash pay surgery. If you have a complication of an operation that insurance did not pay for, insurance is not going to jump in and pay for that complication.