The gastric bypass, or “Roux-en-Y," is a medical weight loss procedure. It works by modifying your digestive system. Gastric bypass surgery reduces the size of your stomach, and also the length of your small intestine. As a result, you consume and absorb fewer calories.
Gastric bypass surgery is a metabolic and weight loss procedure. It’s also known by the French term, “Roux-en-Y." The procedure works by modifying your digestive system so that you consume and absorb fewer calories. It modifies your stomach and also your small intestine.
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Like other bariatric surgery operations, gastric bypass is recommended for people who have clinically severe obesity. It has been shown to help relieve a long list of obesity-related health conditions, including type 2 diabetes, hypertension, obstructive sleep apnea and GERD (chronic acid reflux).
The Roux-en-Y procedure gets its name from the way it changes your digestive system. “Roux-en-Y" means “in the shape of a Y." The procedure divides both your stomach and your small intestine, connecting each new segment together to form a “Y” shape.
First, it reduces the functional part of your stomach to a small pouch, separating it from the rest with surgical staples. This restricts the amount of food that your stomach can hold. Then, it connects the new stomach pouch to a lower segment of your small intestine.
This means that when food goes through your digestive system, it will now bypass most of your stomach and the first part of your small intestine. Because of this bypass, your digestive system won’t absorb all of the nutrients (or calories) in your food.
The Roux-en-Y procedure has been practiced, studied and refined for over 50 years. It was once the most common weight loss surgery, but in recent years it’s been overtaken by the gastric sleeve. Today the gastric bypass represents about 18% of all bariatric surgeries.
Yes. While it is considered a safe procedure, comparable to many other common surgeries, a gastric bypass is a major operation that will change your digestive system forever. Even after recovery, you will have to continue to take special care of it for the rest of your life.
Weight loss in the first year or two after surgery is often significant. The average is about 70% of excess weight. Over the longer term, some people gain some weight back, but the average long-term weight loss is 50% of excess weight. That number holds steady for 20 years.
If you have medically significant obesity, just losing weight can do a lot to improve your health. But gastric bypass surgery does more than that. It makes lasting changes to your metabolic system to help you manage your blood sugar, blood pressure and hunger.
Conditions improved by gastric bypass surgery include:
Gastric bypass surgery requirements are similar to those of other bariatric procedures. You must be recommended for surgery by a qualified healthcare provider. In general, you may be a candidate for gastric bypass surgery if you:
If you’ve met these benchmarks, you may be recommended for surgery. But your surgeon will have additional requirements. Before scheduling your surgery, you’ll meet with a team of healthcare specialists for counseling and screening. They’ll want to know:
Most Roux-en-Y surgery operations today are performed by laparoscopy, a minimally-invasive surgery technique. The laparoscopic gastric bypass was introduced almost 30 years ago and has since become the standard of care for most people.
Laparoscopic surgery involves three to five small incisions in your abdomen, each about a half an inch. Smaller cuts mean fewer complications, less bleeding, less pain and a faster recovery. Your surgeon will perform the operation through these openings, using long, narrow tools.
Sometimes laparoscopic operations such as Roux-en-Y are done with robotic assistance. Robotic surgery is still controlled by the surgeon. It just means that the surgeon attaches robotic arms to the laparoscopic tools. They control the arms with a computer.
While 90% of Roux-en-Y surgeries are performed laparoscopically, some people may need to have open surgery to manage their specific conditions. Rarely, some laparoscopic Roux-en-Y surgeries may need to convert to open surgeries to be completed safely.
All laparoscopic surgeries begin with a single “keyhole incision” in your abdomen. Your surgeon uses this first keyhole to inflate your abdominal cavity with carbon dioxide gas. This helps separate your abdominal wall from your organs and makes everything easier to see.
Then your surgeon will place a tiny lighted video camera called a laparoscope through the keyhole to visualize your organs. The laparoscope will project onto a computer screen. Your surgeon will use additional keyhole incisions to access your organs.
The first step in the Roux-en-Y procedure is to divide the top portion of your stomach from the remainder with a surgical stapler. The resulting pouch is about the size of an egg. The remainder of the stomach is still attached to your small intestine.
The next step is to divide your small intestine several feet down its length and bring the lower segment up to attach to your new stomach pouch. Your food will now pass from your stomach pouch into this segment of your lower small intestine.
The final step is to reattach the upper branch of your small intestine to the trunk further down. Now your small intestine has two branches attached to the trunk: one leading from your stomach pouch, and the other leading from the remainder of your stomach.
The right side of this “Y” is the new branch, the one that your food will pass through. The left side is the original upper part of your small intestine (your duodenum). This is the part where your liver, gallbladder and pancreas deliver their digestive juices.
The left branch will deliver these juices into the new trunk of your small intestine, where they will mix with your food. This will enable you to properly digest your food, even though your shortened intestinal pathway will absorb fewer nutrients from it.
The procedure itself takes between two to four hours. Afterward, you’ll probably remain in the hospital for two days. You won’t be able to eat solid foods yet.
You’ll feel moderate pain in the first few days, but you’ll have pain medication on demand through a catheter in your vein. You won’t be discharged from the hospital until you’ve weaned from your pain medication and are able to move around comfortably on your own.
At home, you’ll have prescription pain medications to take. Most people wean from these within a week. You may continue to feel your incision wounds while they heal, but the smaller laparoscopic surgery incisions heal relatively quickly.
This procedure has the advantage of decades of practice behind it. It’s one of the most thoroughly studied surgeries in modern medicine. Compared to other weight loss procedures, it has one of the best success rates over the long term.
Follow-up studies of gastric bypass surgeries have shown consistent, significant weight loss decades later. Along with weight loss, many related health conditions improve or even resolve. Many people are able to discontinue medications for these conditions.
In the short term, gastric bypass surgery shares the same general risks as many other surgeries, including:
Complications more specific to gastric bypass surgery can include:
Surgeries that modify your digestive system can cause certain digestive complications. These include:
You’ll likely spend a day recovering in the hospital, then a few weeks recovering at home before you feel ready to go back to work. You may need to avoid strenuous activity for up to six weeks, and it may take up to twelve weeks to resume a normal diet.
Your body will be experiencing huge shifts during this time. You may notice:
The rapid weight loss and limited nutrition of the first few months may cause:
You will have strict dietary guidelines to follow for several months after your surgery. This is both to protect your digestive system while it heals and to make sure you get the nutrients you need while taking in less food overall.
You’ll probably start on a liquid diet for the first several weeks, then gradually progress to a soft diet for several more. It might be two to three months before you return to solid foods. When you do, you will have to continue to choose your foods carefully.
Your healthcare team will provide you with more specific dietary guidelines, but they generally include:
You’ll have regular checkups with your healthcare provider over the following months and years. They’ll monitor your general health and weight loss, test you for nutritional deficiencies and continue to provide counseling on the diet and lifestyle changes you’re implementing.
A note from Cleveland Clinic
Gastric bypass surgery is a serious lifelong commitment, but it can provide significant lifelong changes. If you’re prepared to take more intensive care of yourself, eating more mindfully and exercising regularly, surgery can make these changes work for you like never before.
While there is some risk of long-term complications, these can usually be avoided by following self-care guidelines. Compared to the risks of obesity itself and its related health conditions, most people find these risks well worth the reward of weight loss and recovery.
Last reviewed by a Cleveland Clinic medical professional on 04/11/2022.
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