More recently another procedure has been described which seems as efficient on weight loss and co-morbidities as the RYGBP, with the advantage of being less technically difficult and less morbid, especially for multi-complicated obese and/or the super obese. It consists of a unique gastro-jejunal anastomosis between a long gastric pouch and a jejunal Omega loop. However, this procedure could be at risk of biliary reflux and anastomotic ulcers with dysplastic changes of the gastric and esophageal mucosa. As a result, the Omega loop bypass (OLB) has only been developed by a few teams and remains a controversial subject, particularly as only one monocentric randomized trial has compared it to the RYGBP, which is remains the gold standard. The first litterature results show similar or even better weight loss efficiency than RYGBP with a better feasibility. The early complication rate seems lower, but there are still insufficient data on long term morbidity and biliary reflux consequences.