I can only say that, personally, I hope you will not have that surgery. There are two vitally important yahoo groups you might like to check - OSSG Gone Wrong and WLS uncensored. What you read there might surprise you. I have friends on both sites who have gone through various different bypass procedures.
Whatever you decide, very good luck. If you have the surgery you will be on a diet, of sorts, for the rest of your life. And a heckova lot of supplements and blood tests, forever.
But I stress that this is my personal opinion! And only that.