What is RNY Gastric Bypass Surgery?

n RNY surgery, the stomach is completely divided into two compartments —an upper part, or pouch, and the lower portion of the stomach.
Where to cut ?

The upper pouch is smaller, and is made to hold one ounce (about the size of an egg) or less. The small bowel is divided and brought up to the upper stomach where an anastomosis is made between the pouch and the small bowel. An anastomosis is the term surgeons use for the opening formed when they sew, or staple together, two pieces of bowel, making an opening—or stoma—between them. The Y-connection allows pancreatic fluid and bile to aid in absorption of nutrients

The opening between the new pouch and the intestines is called a stoma.
The stoma size keeps food in the pouch, allowing the patient to feel full for several hours on a small amount of food.