Roux-en-Y Gastric Bypass

Roux-en-Y gastric bypass surgery divides the stomach, creating a small gastric pouch, which is reconnected to the small intestine creating restriction and less absorption.

The Procedure

There are two components to the procedure. First, a small stomach pouch, approximately one ounce or 30 milliliters in volume, is created by dividing the top of the stomach from the rest of the stomach. Next, the first portion of the small intestine is divided, and the bottom end of the divided small intestine is brought up and connected to the newly created small stomach pouch. The procedure is completed by connecting the top portion of the divided small intestine to the small intestine further down so that the stomach acids and digestive enzymes from the bypassed stomach and first portion of small intestine will eventually mix with the food.

The gastric bypass works by several mechanisms. First, similar to most bariatric procedures, the newly created stomach pouch is considerably smaller and facilitates significantly smaller meals, which translates into less calories consumed. Additionally, because there is less digestion of food by the smaller stomach pouch, and there is a segment of small intestine that would normally absorb calories as well as nutrients that no longer has food going through it, there is probably to some degree less absorption of calories and nutrients.

Most importantly, the rerouting of the food stream produces changes in gut hormones that promote satiety, suppress hunger, and reverse one of the primary mechanisms obesity induces type 2 diabetes.

Advantages

• Produces significant long-term weight loss (60 to 80 percent excess weight loss).
• Restricts the amount of food that can be consumed.
• This may lead to conditions that increase energy expenditure.
• Produces favorable changes in gut hormones that reduce appetite and enhance satiety.
• Typical maintenance of >50 percent excess weight loss.

Disadvantages

• It is technically a more complex operation than the Adjustable Gastric Band or Laparoscopic Sleeve Gastrectomy and potentially could result in greater complication rates.
• This can lead to long-term vitamin/mineral deficiencies, particularly vitamin B12, iron, calcium, and folate deficits. Requires adherence to dietary recommendations, life-long vitamin/mineral supplementation, and follow-up compliance.

Education

You will receive information about gastric bypass during your initial consultation.

Review a procedure animation video of the gastric bypass to understand the procedure better. 

The photo was reprinted with permission from the American Society for Metabolic and Bariatric Surgery. Copyright 2015; all rights reserved.