How Does Roux-en-Y Gastric Bypass Surgery Work?

Roux-en-Y is a restrictive and malabsorptive procedure. The restrictive component of this bypass procedure involves the reduction of the volume of the stomach. A smaller stomach makes patients feel fuller without eating a lot of food. The malabsorptive component of Roux-en-Y involves the bypass of a portion of the stomach and the small bowel. As a result patients are unable to fully absorb the calories contained in their meals.

Specifically, the surgeon divides the stomach into two parts; an upper small part and a lower bigger part. The two parts of the stomach are then sealed so that two separate compartments will exist. The pouch (upper small compartment) receives the food from the esophagus, while the lower compartment never comes into contact with food. Next, the pouch is connected to the lower section of the small intestine. This way food skips part of the stomach and the small bowel. Food goes from the mouth to the esophagus to the pouch and to the lower small intestine, bypassing the lower stomach and the initial part of the small intestine.

Expected Weight Loss After Roux-en-Y Gastric Bypass Surgery

Roux-en-Y patients lose on average 70% of their excess weight within 19 months, according to the 2009 study by Strain and colleagues.

Pros

• Roux-en-Y gastric bypass is the most studied, most successful, and most commonly performed weight loss surgery in the US, according to the American Society of Bariatric Surgery. It is the bariatric procedure of choice and current standard of care in the US.

• Roux-en-Y patients lose more excess weight than gastric band patients.

• Roux-en-Y patients are less likely to regain weight than gastric band patients. The weight is not gained back even after 10 years post-operatively

Cons

• Irreversible. Roux-en-Y permanently changes the anatomy of your internal digestive organs.

• As surgeon Dr. Peter LePort says, while weight regain is less likely than purely restrictive procedures, roux-en-Y patients can gain all their weight back if they do not conform to their prescribed diet i.e., “they eat so fast that they stretch everything out so they can eat more and then they start eating like they were before”.

Risks and Complications of Roux-en-Y Gastric Bypass Surgery

• Malnutrition. Roux-en-Y gastric bypass significantly reduces the patient’s nutrient absorption capacity. Without consistent vitamin and protein supplementation, the risk of nutrient deficiency and anemia is high.

• Dumping syndrome. The Roux-en-Y procedure allows food to skip the pyloric valve, the sphincter muscle is at the lower part of the stomach and controls how quickly food enters the intestines. Food goes directly from the upper part of the stomach (pouch) to the lower end of the small intestine and there is nothing to limit how fast it moves. As a result of the food moving too quickly through the body causing nausea, sweat and faintness.

• Infection, blood loss and clots. Roux-en-Y surgery is more invasive than the gastric band procedure and therefore the risk for blood loss, blood clots and infection at the site of incision is higher.

• Other complications of Roux-en-Y include the development of gallstones, stomach leaks, hernias and bowel obstruction.

• The risk of death ranges 0.3-1.0%

About the author
Matthew Denos, PhD, is a biologist who writes on a wide range of weight loss surgery topics, including gastric bypass financial help.

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