That means they no longer need sugar-control medication, like insulin injections.
One patient, Vicki, told Stahl she went from having eight or nine insulin shots a day to none, and that she's diabetes free - "cured" as she put it.
"Would you use the term 'cure diabetes?'" Stahl asks Dr. Hutcher.
"I think my patients are cured," he says.
"Cured?" Stahl asks.
"Well, they go home on no medication," he says. "And I've followed them now for 10 and 15 years, and see no evidence of recurrence. So, it's pretty darn close."
Studies confirm that about 80 percent of diabetics go into complete remission following the operation. Obesity is considered one of the major causes of type 2 diabetes, but here's something odd: when you have the gastric bypass operation, your diabetes goes away long before you lose the weight.
For Travis, the man who lost 260 pounds in seven months, it took "about a week and a half" before he was rid of diabetes and off all his medication.
Another male patient named Bill said it took him four days. "I went into the hospital on Friday, came home on Monday and dumped my pills," he told Stahl.
This spontaneous remission puzzled Italian surgeon Francesco Rubino, now at New York Presbyterian Weill Cornell Medical Center. "We wanted to know what is making diabetes remit. We thought it could have been something to do with the small bowel," Dr. Rubino says.
So he began performing the bypass on diabetic rats, and realized that when he disconnected the top of the small intestine, an area called the duodenum, the diabetes disappeared. Then, he reversed the operation.
When he reattached it, the diabetes came back.
This was a pivotal discovery. By merely blocking food from traveling through the duodenum, Rubino sent diabetes into remission, proving the effect was independent from weight loss. This meant diabetes could essentially be removed with a scalpel.
Dr. Rubino says this operation has been performed on humans.
60 Minutes joined him in Sao Paulo, Brazil, where clinical trials have begun on diabetics who are not obese, to determine if the "diabetes surgery" is safe and effective.
As of now, if you have diabetes and are not obese you can't have the bypass surgery. Under guidelines written by the National Institutes of Health 17 years ago in 1991, only the severely or morbidly obese are eligible for any bariatric operation. If you're just mildly obese, you can't get it.
"And a lot has changed since 1991," Dr. Hutcher remarks. "I would like to see them change their guidelines, especially for the diabetics. I think we have clear cut evidence that we can do terrific things for diabetes."