We were told in our WLS Seminar (as well as I've heard it on the news) that bypass and the sleeve can be almost an instant fix for diabetes - by the time you leave the hospital most people are no longer diabetic because they remove or bypass the portion of your stomach that secrets the chemical that is responsible for diabetes. From the news article I read:
"There were signs that the surgery itself - not just weight loss - reverses diabetes. food makes the gut produce hormones to spur insulin, so doctors think trimming away part of it surgically may affect those hormones.
Weight-loss surgery "has proven to be a very appropriate and excellent treatment for diabetes," said one study co-leader, Dr. Francesco Rubino, chief of diabetes surgery at New York-Presbyterian Hospital/Weill Cornell Medical Center. "The most proper name for the surgery would be diabetes surgery."
Lap Band is also effective with this, just not as quickly as the other two.
Again, take this with a grain of salt...I got it off the internet afterall