Sleeve Gastrectomy in patients with a BMI of over 50 generally leads to very high rates of insufficient weight loss and late weight regain. There are various methods of revisional surgery to obtain further weight loss. The most effective and invasive has been conversion to Duodenal Switch. Traditional Duodenal Switch procedures have high rates of nutrient deficiencies and alteration in bowel habit. To alleviate these problems and decrease perioperative morbidity, various versions of the SADI procedure (Single Anastomosis Duodeno-Ileostomy) have been proposed. I will present the theory behind the development of SADI, evidence following conversion from sleeve gastrectomy to SADI and my experience in this area.