Bariatric Surgery Patient Information

Bariatric surgery is a tool to help with weight loss. It is often called weight loss surgery, but it is not a cure for obesity. People who have the surgery need to make lifestyle changes. A healthy diet and regular exercise are needed along with surgery for permanent weight loss.

Who can have bariatric surgery?

Bariatric surgery is not an option for everyone. It is only for people who are very overweight. BMI (body mass index) is based on a person’s height and weight. It is a better way to see if you are overweight or obese than by looking only at your weight. To be considered for bariatric surgery, you must:

  •  have a BMI of 40 or greater
  • or have a BMI of 35 and a medical condition that is linked with obesity. These medical conditions include type II diabetes, breathing difficulties, heart problems, joint problems, and high blood pressure.

You must also:

  • have tried and failed to lose weight and keep it off with diet, exercise, or medicine supervised by your doctor
  • agree to make lifelong changes in eating and exercise habits
  • agree to lifelong medical follow-up

Learn more about your BMI and see our BMI calculator:


Some medical problems that may improve after bariatric surgery are:

  • Diabetes
  • High blood pressure
  • Heartburn and GERD (gastric esophageal reflux disease) 
  • Sleep apnea
  • Breathing problems

Types of surgeries

There are 2 types of surgeries used for weight loss.

  • “Restrictive” procedures make the stomach smaller. This "restricts" or limits the amount of food you can eat at one time.
  • “Malabsorptive” procedures change the way food is digested. Part of the small intestine is “bypassed” or skipped. This reduces the amount of food that the body can absorb. It also decreases the amount of vitamins and minerals that the body absorbs. People who have a “malabsorptive” procedure have to take vitamin and mineral supplements for the rest of their lives.

Gastric banding

There are 2 common types of gastric banding surgery. One is the LAP-BAND system. The other is vertical gastric banding. Both are “restrictive” surgeries. A band is wrapped around the upper part of the stomach. There is a small “pouch” above the band. There is also a path from the pouch to the rest of the stomach. Because the pouch is small, only small amounts of food can be eaten at one time. The opening from the pouch to the rest of the stomach is also small. This keeps food in the pouch lon¬ger so you feel full longer.

With the LAP-BAND system, the band can be adjusted by injecting salt water (saline) through a port into the band. This makes the opening from the pouch to the rest of the stomach smaller or bigger. If you do not chew your food well or you eat too much at one time, you may vomit. Most patients keep losing weight for 18 to 24 months after surgery if they follow their diet and exercise guidelines.

Gastric bypass

Gastric bypass is both a “restrictive” and a “malabsorptive” surgery. A pouch is made to limit the amount of food that can be eaten at one time. A part of the small intestine is attached to the pouch. This bypasses the main part of the stomach and some of the small intestine.

Because of this bypass, the body does not absorb as much food. The intestines do not absorb as many vitamins and minerals. Because of this, you must take vitamin and mineral supplements for the rest of your life. Bowel movements may be looser and more frequent. This is usually temporary. Weight loss happens during the first 12 to 18 months after surgery if you follow diet and exercise guidelines.

After surgery

After surgery, you will only be allowed to have clear liquids. You will gradually move to pureed or soft foods. Eventually, you will move to regular foods but in small portions. It is very important to chew foods well. You need to stop eating as soon as you feel full. You also need to drink at least 8 glasses (64 ounces) of liquid during the day.

Exercise is also very important after surgery. Walking is a good way to start. You should increase the amount of exercise slowly. Talk to your doctor before beginning an exercise program. Medical follow-up after bariatric surgery is for the rest of your life. After your surgery, you will need to follow up with your surgeon or doctor regularly.

When to call your doctor after bariatric surgery

Call your doctor if you notice any of the following:

  • Dehydration
  • Nausea or vomiting
  • Fever
  • Redness, swelling, or draining from the incision site
  • Shortness of breath
  • Chest pain
  • Calf pain

If you would like more information about bariatric surgery, please call 1-800-533-UPMC (8762) or visit

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For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

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Medical information made available on is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

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