Gastric bypass surgery (Roux-en-Y)

What is gastric bypass surgery (Roux-en-Y)?

Gastric bypass surgery, also called Roux-en-Y (roo-en-why), is a proven, safe, and effective long-term treatment for obesity. During gastric bypass surgery, a bariatric surgeon creates a very small pouch from the top portion of your stomach. They separate the pouch from the rest of your stomach and attach it to a section of your small intestine.

After gastric bypass, food being digested empties from this tiny stomach pouch through a stoma (opening) into your intestine. It bypasses (goes around) the rest of your stomach and upper small intestine.

How gastric bypass surgery helps you lose weight

After you have gastric bypass surgery, your new stomach pouch will only accommodate small portions of food. Because food bypasses part of your small intestine, you absorb fewer calories and nutrients. Your body will also produce lower levels of ghrelin, the hormone that makes you feel hungry.

Together, these factors can lead to significant weight loss. Results vary, but many patients lose between 50 percent and 80 percent of their excess body weight within 18 months when they incorporate healthy lifestyle habits.

Gastric bypass is a complicated procedure. We typically recommend it for people with a BMI over 45, as it helps them lose more weight than other surgical options. It also helps resolve type 2 diabetes faster than other procedures.

Who is a candidate for gastric bypass surgery?

Candidates for gastric bypass surgery at Penn Medicine must meet specific criteria established by the National Institutes of Health (NIH). Most insurance companies follow these requirements.

Requirements include:

  • A body mass index (BMI) greater than 40, or a BMI greater than 35 with medical complications related to obesity
  • Previous attempts to lose weight
  • No active drug or alcohol abuse or major psychiatric disorder

During your evaluation for bariatric surgery, our team will make sure you understand all requirements and eligibility for bariatric surgery and ensure gastric bypass is appropriate for you.

What to expect during gastric bypass

Before your procedure, your surgeon will explain the details of gastric bypass and answer all your questions. You will also meet with one of our dieticians to prepare for diet changes before and after bariatric surgery.

On the day of surgery, you will have general anesthesia, to make sure you stay asleep and comfortable throughout the procedure. Our skilled bariatric surgery team uses minimally invasive laparoscopic techniques for most gastric bypass procedures. These techniques use only a few small incisions.

Recovery from gastric bypass surgery

Most people recover in the hospital for one or two days after gastric bypass surgery and don’t need special care when they go home. You should not drive until you stop taking medications associated with surgery and can move quickly. You may return to work within one to two weeks of surgery, in many cases. If you have a physically demanding job, it may take up to six weeks before you can work.

Benefits and risks of gastric bypass surgery

The benefits of gastric bypass surgery include more than just weight loss. Bariatric surgery can prevent or improve many weight-related health conditions. After surgery and weight loss, you may experience:

  • Better energy levels
  • Decreased risk of heart disease and cancer
  • Fewer respiratory complications
  • Lower blood pressure
  • Sleep apnea elimination 
  • Type 2 diabetes remission

Although it’s a safe and effective weight loss procedure, gastric bypass surgery carries the same risks as any major surgery. These include:

  • Bleeding and blood clots
  • Hernia through the incision or inside of the abdomen
  • Infection of the incision or abdomen
  • Intestinal blockage caused by scar tissue

After surgery, you may experience one or more of the following side effects (these are rare):

  • Dumping syndrome from high-fat or high-sugar foods
  • Reactive hypoglycemia or low blood sugar between meals
  • Ulcers from smoking or using non-steroidal anti-inflammatory drugs (NSAIDs)
  • Steatorrhea (a type of diarrhea) caused by eating high-fat foods
  • Stricture or narrowing of opening to intestines
  • Vitamin or mineral deficiency

World-class bariatric surgery care from board-certified surgeons

The bariatric surgeons at Penn Medicine have training and expertise in the latest surgical procedures for weight loss to help you achieve long-lasting results. We offer minimally invasive endoscopic, laparoscopic, and robotic procedures. Because every patient is unique, our program includes a full range of options, ensuring you receive the bariatric surgery that’s right for you.

Our bariatric programs in Philadelphia, Lancaster, and Princeton have accreditation from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). Our expertise in bariatric surgery nursing has earned our team Magnet® status from the American Nurses Credentialing Center (ANCC).

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