What is a Roux-En-Y Gastric Bypass?

Roux-en-Y gastric bypass is a type of bariatric surgery to treat morbid obesity. It is the most common type of gastric bypass and the most common bariatric procedure. As of 2010, Roux-en-Y gastric bypass was considered the "gold standard" for weight loss surgery.

All gastric bypass procedures, including Roux-en-Y, are only for individuals who are morbidly obese. A doctor would not recommend it for a mildly or moderately overweight patient. Gastric bypass surgery might be indicated if a patient is more than 100 pounds overweight, has a body mass index of 40 or higher or has a body mass index of 35 or higher along with obesity-related medical problems.

There are two types of Roux-en-Y gastric bypass procedures. During both, the surgeon’s aim is to decrease the stomach's size and change where the stomach meets the small intestine. With the distal method, the surgeon creates a small stomach pouch and connects it to the lower, or distal, section of the small intestine. During digestion, most calories and nutrients are absorbed through the small intestine. In bypassing a large section of the small intestine, the surgery allows the body to absorb fewer calories.

With the proximal method of Roux-en-Y gastric bypass, the surgeon connects the stomach pouch to the upper, or proximal, part of the small intestine. The proximal method allows for better absorption of calories and nutrients through the small intestine. This means that weight loss might not be as great, but there are fewer nutritional problems than with the distal method. With both methods, the newly created, smaller stomach pouch severely restricts the amount and types of food that he or she can consume. The food also leaves the stomach pouch slowly, which causes the patient to feel satiated for longer.

There are considerable risks with the Roux-en-Y gastric bypass, though complications with this method are fewer than with other forms of bariatric surgery. Some possible complications include infection, hemorrhage, nutritional deficiencies and leakage at the connection between the stomach pouch and small intestine. In some cases, the connection can become smaller over time and will no longer allow food or liquid to pass through. Another possibility is “dumping syndrome,” which occurs when a patient eats too much sugar or food. The food is “dumped” into the small intestine, causing nausea, weakness, fainting and diarrhea.

Roux-en-Y gastric bypass requires major lifestyle and dietary changes. After surgery, patients must learn a new way of eating and follow strict dietary guidelines. Patients also require more frequent, regular checkups with their doctors.

For many people who are considering Roux-en-Y gastric bypass, the benefits outweigh the potential risks. According to the University of Rochester Medical Center, patients lose up to 77 percent of their excess weight within a year. In one study of 500 patients, 96 percent of obesity-related health problems had resolved or improved after gastric bypass.