The single anastomosis gastric bypass is also known as an Omega loop bypass or a “mini” gastric bypass.
Similar to a Roux-en-Y bypass, it begins with creating a smaller stomach pouch. This is done using a stapling device via a laparoscopic (key hole) technique. After the pouch is created, it is joined to the small bowel approximately 2m downstream. Hence the term mini or single loop- as there is only one anastomosis, or join.
The end result is that the digestive fluids from the liver/pancreas and food meet further downstream, and there is a shorter “common channel” for the digestion and absorption of nutrients.