Gastric Bypass

Gastric bypass diagram

The Roux-en-Y gastric bypass is commonly referred to as gastric bypass, Roux-en-Y or RNY. It is a more complex operation, and is considered the gold standard operation in regard to overall weight loss and the reduction or resolution of comorbidities. It is the operation that has been around the longest and is typically done laparoscopically.

Roux-en-Y bypass surgery uses a combination of restriction and malabsorption.

The small upper pouch (1/2 ounce) is completely separated from the distal stomach which is left in place. A “Y” shaped segment of small bowel is attached to the pouch with a narrow opening. This allows food to bypass a large portion of the small intestine, which absorbs calories and nutrients. The procedure both restricts food intake and results in malabsorption resulting in more consistent weight loss, but has a higher risk of complications or side effects. Studies show 80 percent of patients lose at least half their excess weight with the RNY procedure.

This procedure can be done both by the laparoscopic or open approach.

Gastric Bypass surgery has advantages of intestinal and hormonal metabolic effects not seen with Adjustable Gastric Band and Laparoscopic Gastric Sleeve. These changes lead to more rapid weight loss, greater overall weight loss, and more immediate improvement in obesity related diseases, especially diabetes.

Laparoscopic or Open?

Weight loss surgery at Virginia Mason is done both laparoscopically and open.


The benefits of the laparoscopic approach are:

  • Wound hernias are extremely rare with laparoscopic surgery because the incisions are so small
  • Patients have much less pain with smaller incisions
  • Patients typically stay in the hospital one to two nights
  • Lower rate of post-surgical infection
  • Generally, a shorter recovery period

Open Approach

Not all patients are suitable for the laparoscopic approach for weight loss surgery.

Open surgery may be more beneficial for:

  • Patients who have had prior abdominal surgery
  • Patients with large amounts of scar tissue or hernia mesh
  • Patients with complicated medical problems
  • Patients who are extremely obese

Both the laparoscopic and open approaches to weight loss surgery produce similar long-term results. The open approach is generally associated with a longer recovery period.

Virginia Mason offers bariatric surgery services at two convenient locations in Seattle and Federal Way. You can reach the bariatric surgery team by calling (206) 341-1997 or toll-free at (800) 354-9527, ext. 11997.