Weight Loss Surgery Health Center

Bariatric surgery -- or weight loss surgery -- works in three basic ways: 1) restricting how much food your stomach can hold at any time, 2) preventing your digestive system from absorbing all the nutrition in the food you eat, or 3) a combination of these two ways. This guide uses imagery and animation to show you what to expect from weight loss surgery.

• Body mass index (BMI) greater than 40.
• BMI of 35-40 for people with heart disease, diabetes, high cholesterol, or obstructive sleep apnea. Calculate your BMI

In general, doctors operate on people who have been unable to achieve lasting weight loss with lifestyle changes and medications aimed at weight loss. Some doctors require patients to lose some weight before having surgery.

Gastric banding and gastroplasty ("stomach stapling") are restrictive procedures that decrease the stomach size from about six cups to one. Malabsorptive procedures, which block food absorption, include gastric bypass. "Roux-en-Y" gastric bypass combines both approaches and is the most common weight loss surgery in the U.S. It reduces the size of the stomach and prevents the absorption of calories in the small intestine.

Before you have weight loss surgery, you'll go through an evaluation process that includes counseling and various tests. One-on-one counseling takes all your individual needs and preferences into account to help you choose the best type of bariatric surgery for you.

Preparation will depend on the specific procedure, and may include blood typing and other screening tests. You’ll avoid aspirin or aspirin-containing products and herbal supplements one week prior to surgery, and take only clear liquids for 24-48 hours immediately before surgery. An IV will be started to provide pain medication and sedation. Then, once you are asleep, a breathing tube will be inserted to help you breathe during the operation.

Your surgeon will use either the open or laparoscopic surgical method for your gastric bypass surgery, as shown in this animation.

During a "Roux-en-Y" gastric bypass procedure, surgical staples are used to create a small pouch to serve as your new stomach.

By bypassing the lower stomach and part of the small intestine, fewer calories will be absorbed as food passes through it. The stomach remains intact; it secrets digestive juices that aid in digestion in the small intestine.

Banding shrinks the stomach to a small pouch and shrinks the exit to a very small opening so food moves through slowly, making you feel full longer.

This malapsorptive procedure greatly decreases the calories and nutrients absorbed in the small intestine.

For all methods of bariatric surgery, your surgeon will close the incision using surgical stitches or staples. Your IV and breathing tube will be removed and you will be monitored during a short hospital stay. Pain medications will be administered.

Laparoscopy leaves smaller scars than open surgery and tends to have fewer complications and quicker recovery time. Ninety percent of gastric bypasses are done this way.

For a day or two, you'll drink tiny amounts of clear liquids such as water, fruit juice, and broth. Then come denser liquids like milk, smooth cooked cereal, and pudding. For three to four weeks, you'll eat frequent tiny portions of pureed foods. In the second month, you may eat soft, moist, ground-up foods. Three months after bariatric surgery, you may be back to a regular diet. But, you won’t be able to eat big portions again.

Weight loss may be dramatic in some cases -- as much as a pound a day in the first three months. Combination surgery that causes malabsorption and shrinks the stomach produces more weight loss than restriction-only operations. People who have bypass surgery generally lose two-thirds of their excess weight within two years.

Excess skin may need to be removed after rapid weight loss. This requires additional surgery.

If you have high blood pressure, diabetes, or other health problems that are caused by being overweight, they may improve or go away as you lose weight. Your doctor will work with you to adjust any medications you take for those conditions. With successful weight loss, people with arthritis and sleep apnea also see improvements in their well-being. Often there is a dramatic improvement in joint pain, breathing, and sleep, as well as the ability to engage in physical activity.

Weight loss surgery can produce dramatic results. But the gains from losing weight are not automatic. The process requires permanent lifestyle changes to be successful, including eating small frequent meals, committing to good nutrition, and exercise.

All surgeries carry some risk. For bariatric surgery, the risk of dying is less than 1% and serious complications are rare. To have the best chance of avoiding complications, it's important to go to all your follow-up visits and stick to your prescribed diet and lifestyle plan.

People who undergo bariatric surgery are at risk for complications including:

• Pouch stretching back to stomach's original size
• Vomiting from eating more than the stomach pouch can hold
• The band disintegrating
• Band and staples fall apart, reversing the procedure
• Stomach contents leaking into the abdomen
• Gallstones from excess weight loss
• Nutritional deficiencies and health problems

Gastric bypass surgery also may cause the stomach contents to move too rapidly through the small intestine. Symptoms include nausea, weakness, sweating, faintness, and, occasionally, diarrhea after eating, as well as the inability to eat sweets without becoming extremely weak. To avoid these symptoms, follow the dietary recommendations of your nutritionist.

After surgery, many people have reduced absorption of vitamin B-12, iron, and calcium. The more extensive the surgery, the greater the risk for nutritional deficiencies. Supplements boost your intake of these nutrients and prevent anemia and osteoporosis. Most people will require close monitoring and the lifelong use of special foods and medications.

Although gastric banding is considered the least invasive of the weight loss surgeries, problems can occur, including:

• Band slippage
• The passageway created by the band can be blocked by food
• Access port leakage or infection
• Esophagitis or gastroesophageal reflux disease (GERD)
• Malnutrition

It is common to have many different emotions after weight loss surgery. You may feel happy or excited as you begin to lose weight. But you may also feel overwhelmed or frustrated by the changes that you have to make in your diet, activity, and lifestyle. Talk with your doctor if you have concerns or questions.