Laparoscopic Duodeno-jejunal Bypass was and still is in its experimental phase. Initial studies on human subjects proved short term remission from Type II Diabetes in non-obese individuals BMI < 30.
These studies were initially carried out by Dr. Francisco Rubino and later on by Dr. Almino Ramos. They stemmed from the benefit seen in bypass procedures for obesity in treating Type II Diabetes.
The procedure involves just bypassing the duodenum and initial part of the jejunum while the stomach remains completely intact. This bypass alters certain hormones in the gastrointestinal tract that promote insulin sensitivity, thus improving blood sugar control and Diabetes.
No newer results have been published, and longer-term results do not seem to be promising when discussed informally, and the procedure seems to have been abandoned by its investigators