Laparoscopic Roux-en-Y Gastric Bypass

Why is Gastric Bypass the Most Popular Weight Loss Operation in the United States?

The Roux-en-Y (pronounced "roo-on-why") gastric bypass is currently the most commonly performed weight loss operation in the United States. Roughly 70% of American weight loss surgeons use it as their primary weight loss operation. It has been around for over 30 years and has been demonstrated over and over to provide an excellent balance of weight loss and manageable side effects. For these reasons, the gastric bypass is considered by many surgeons and patients alike to represent the best alternative in weight loss surgery.

The operation can be performed either laparoscopically, through 5 very small incisions in the abdominal wall, or open, through a traditional midline abdominal incision. In general, we prefer the laparoscopic approach at Mount Sinai because of decreased pain, faster recovery, quicker return to normal activities, and a lower incidence of incision-related problems like infection or hernia.

In the Roux-en-Y gastric bypass procedure, a surgical stapler is used to separate the upper portion of the stomach from the lower portion. The upper portion, only 1 to 2 tablespoons in size, is referred to as the "pouch," and is the only part of your stomach that food enters into. This pouch is then connected to a limb of small intestine called the "Roux limb." The alimentary limb is the branch of the "Y" through which food passes. The biliopancreatic limb contains the digestive juices (bile and pancreatic juice). Food finally mixes with the digestive juices in the "common channel", the part of small intestine downstream from the Y connection.

How Does the Gastric Bypass Work?

The gastric bypass operation help you to lose weight by 4 different mechanisms:

  • Restriction: The stomach pouch is only 15 to 30 mL in size -- that's just 1 or 2 tablespoons! The pouch fills up very quickly after eating only a small amount of food, and provides a sensation of fullness. Thus, the small pouch places a physical restriction on the amount of food you are able to eat (or want to eat) at one sitting.
  • Malabsorption: While not primarily a malabsorptive operation, the gastric bypass does decrease absorption of some nutrients. Because of this, it will be necessary to talk vitamin and mineral supplements after the operation.
  • "Dumping Syndrome" This occurs if you eat concentrated sweets or carbohydrates after the operation. While everyone experiences dumping a little differently, patients may feed hot and sweaty, cold and clammy, or like they're going to faint. Dumping syndrome is an intentional side effect of the operation! It has been called the "postop police officer" since it strongly discourages sweet eating. It is important to remember that most people do not experience dumping on a regular basis, since they very quickly learn to avoid the sweet foods that cause it.
  • Hormonal Changes: Ghrelin is a hormone produced by the stomach that causes you to feel hungry at mealtimes. Some recent research suggests that gastric bypass may substantially reduce ghrelin levels, resulting in decreased feelings of hunger.


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