Bariatric Surgery

Medically Reviewed By William C. Lloyd III, MD, FACS
Was this helpful?

What is bariatric surgery?

Bariatric surgery refers to weight-loss surgery. Bariatric surgery can help obese adults and adolescents achieve significant weight loss. Weight loss can lower the risk of heart disease and resolve and improve  diseases associated with obesity. This includes type 2 diabetes, hypertension, and high cholesterol. Bariatric surgery requires a lifelong commitment to healthy dietary and exercise habits, vitamin supplementation, and regular follow-up care.  

Bariatric surgery can be a life-saving treatment for people whose obesity seriously threatens their health. Bariatric surgery is used for people who have not lost weight through diet, exercise, counseling, and medication.

Bariatric surgery is only one part of a complex obesity treatment plan. Less invasive treatment options that have less risk of complications are available to help you lose weight. Consider getting a second opinion about your treatment choices before having bariatric surgery. 

Types of bariatric surgery

Bariatric surgeries incorporate one or two general techniques that work in different ways to reduce your calorie intake. These include:

  • Restrictive procedures reduce the size of the stomach. This limits the amount of food you can eat. Restrictive procedures include adjustable gastric banding (Lap-Band), vertical sleeve gastrectomy (stomach stapling), and vertical banded gastroplasty (stomach stapling and banding).

  • Malabsorptive/restrictive procedures (gastric bypass) alter the normal digestion process. The stomach is stapled down to a small pouch (typically the size of a small test tube). It is then attached to the middle of the small intestine. This allows food to bypass most or all of the first section of the small intestine (the duodenum). It reduces the amount of calories and nutrients absorbed into the body. Procedures include the Roux-en-Y gastric bypass (RYGB) and the biliopancreatic diversion with a duodenal switch (BPD-DS). This technique combines the restrictive and malabsorptive procedures to increase weight loss success.

Why is bariatric surgery performed? 

Your doctor may recommend bariatric surgery to treat obesity and reduce the risk of life-threatening complications of obesity. Complications include diabetes, heart disease, and severe sleep apnea

Bariatric surgery is not a treatment option for people who are mildly overweight. It is generally used for adults with a body mass index (BMI) of 40 or more. This means being about 100 pounds overweight for men and 80 pounds overweight for women. People who are less obese with a BMI of about 35 to 39.9 and have serious weight-related health problems, such as type 2 diabetes or high blood pressure may also have bariatric surgery.

Bariatric surgery may be an option if other treatment options that involve less risk and fewer complications have not helped you lose weight. Other options include diet, exercise, behavioral and nutritional counseling, and medication. Ask your doctor about all of your treatment options and consider getting a second opinion before having bariatric surgery.

Who performs bariatric surgery?

A bariatric surgeon or general surgeon performs bariatric surgery. Bariatric surgeons are often general surgeons who have specialized in bariatrics. Bariatrics is the field of medicine that deals with the causes, prevention, and treatment of obesity. A general surgeon specializes in the surgical treatment of a wide variety of diseases, disorders and conditions. 

How is bariatric surgery performed?

Your bariatric surgery will be performed in a hospital. It is often a minimally invasive surgery. This involves  inserting special instruments and a laparoscope through small incisions in the abdomen. The laparoscope is a long, thin camera that transmits pictures of the inside of your body to a video screen viewed by the doctor during surgery.

Minimally invasive surgery generally involves a faster recovery and less pain than open surgery. This is because it causes less trauma to tissues and organs. Your surgeon will make several small incisions instead of a larger one used in open surgery. Surgical tools are threaded around muscles and tissues instead of cutting through or displacing them as in open surgery.

Your surgeon will determine if you are a good candidate for minimally invasive bariatric surgery. Your surgeon will decide how long you need to stay in the hospital based on your diagnosis, age, medical history, general health, and possibly your personal preference. 

Surgical approaches to restrictive bariatric procedures

A restrictive procedure helps you lose weight by reducing the size of your stomach and the amount of food you can eat. Procedures include:

  • Adjustable gastric banding (AGB, Lap-Band surgery, gastric band surgery) involves attaching an inflatable band (called a gastric band) around the top portion of the stomach. The surgeon tightens the band like a belt to form a smaller stomach. Your physician adjusts the size of the stomach by adding or removing saline (salt water) to the band through a port. The port is inserted in the tissue just under your skin in your abdominal wall.

  • Vertical sleeve gastrectomy (VSG, gastric sleeve surgery, gastric sleeve resection, tube gastrectomy) involves removing part of the stomach and using staples to create a smaller tube-shaped stomach. It is the first step of a two-step surgery. The second surgery is a Roux-en-Y gastric bypass (RYGB) or less commonly, a biliopancreatic diversion with a duodenal switch (BPD). The second surgery is performed after the patient has lost sufficient weight to be healthy enough to undergo this more complex procedure. In some cases, VSG by itself has been shown to be effective in achieving significant and fast weight loss. 

Surgical approaches to malabsorptive/restrictive bariatric procedures

A malabsorptive/restrictive procedure helps you lose weight by reducing the size of your stomach and the amount of food you can eat. It also changes the normal digestion process. This reduces the amount of calories and nutrients that are absorbed into the body. Procedures include:

  • Biliopancreatic diversion with a duodenal switch (BPD-DS, duodenal switch) is performed by removing part of the stomach and using staples to create a smaller tube-shaped stomach (vertical sleeve gastrectomy). In another surgery, the stomach is attached to the middle of the small intestine. Food then bypasses a large part of the small intestine, reducing the amount of calories and nutrients that are absorbed into the body. Bile and other digestive juices are also diverted to further reduce digestion. This is a high-risk surgery that is less commonly performed due to many of the potential long-term health risks.

  • Roux-en-Y gastric bypass (RYGB) involves stapling the stomach to create a small pouch that holds less food. The new stomach pouch is attached directly to the middle of the small intestine. This allows food to bypass much of the stomach and the first section of the small intestines. This reduces the amount of calories and nutrients that are absorbed into the body.

Types of anesthesia that may be used

General anesthesia is used for bariatric surgery. General anesthesia is a combination of intravenous (IV) medications and gases that put you in a deep sleep. You are unaware of the procedure and do not feel any pain. 

What to expect the day of your bariatric surgery

The day of your surgery, you can generally expect to:

  • Talk with a nurse who will perform an exam and ensure that all needed tests are in order. The nurse can also answer questions and will make sure you understand and sign the surgical consent form.

  • Remove all clothing and jewelry and dress in a hospital gown. It is a good idea to leave all jewelry and valuables at home or with a family member. Your care team will give you blankets for modesty and warmth.

  • Talk with the anesthesiologist or nurse anesthetist about your medical history and the type of anesthesia you will have.

  • A surgical team member will start an IV.

  • You may be given an injection of blood thinner to reduce the risks of blood clots during surgery

  • The anesthesiologist or nurse anesthetist will start your anesthesia.

  • A tube will be placed in your windpipe to protect and control breathing during general anesthesia. You will not feel or remember this or the surgery as they happen.

  • The surgical team will monitor your vital signs and other critical body functions. This occurs throughout the surgery and during recovery until you are alert, breathing effectively, and your vital signs are stable.

What are the risks and potential complications of bariatric surgery?  

As with all surgeries, bariatric surgery involves risks and possible complications. Complications may become serious and life threatening in some cases. Complications can develop during surgery or recovery.

General risks of surgery 

The general risks of surgery include: 

  • Anesthesia reaction, such as an allergic reaction and problems with breathing

  • Bleeding or hemorrhage (heavy bleeding), which can lead to shock

  • Blood clots, in particular a deep vein thrombosis 

  • Death

  • Infection 

  • Pneumonia

Potential complications of bariatric surgery

Complications of bariatric surgery include:

  • Constipation

  • Damage to abdominal organs or major blood vessels

  • Dehydration 

  • Difficulty swallowing (dysphagia)

  • Dumping syndrome (rapid emptying of stomach contents into the small intestine causing symptoms, such as nausea, vomiting, cramping, and abdominal pain)

  • Gallstones

  • Gastritis (irritated stomach tissue), gastroesophageal reflux (regurgitation), and heartburn 

  • Hernia

  • Intestinal stricture (narrowing) 

  • Leaking of digested foods and digestive juices into the abdominal cavity from the area where the stomach and intestines are sewed together 

  • Malnutrition, including vitamin and mineral deficiencies, which can lead to long-term complications, such as osteoporosis, anemia, and permanent nervous system damage

  • Nausea, vomiting, gas, and bloating

  • Poor weight loss results or inability to maintain long-term weight loss 

  • Slippage, deflation or erosion of the gastric band or obstruction of the stomach opening created by a gastric band

Reducing your risk of complications

You can reduce the risk of certain complications by following your treatment plan and:

  • Following activity, dietary and lifestyle restrictions and recommendations before and after surgery

  • Notifying your doctor immediately of any concerns, such as bleeding, fever, increase in pain, or wound redness, swelling or drainage 

  • Taking your medications and vitamin and mineral supplements exactly as directed 

  • Telling all members of your care team if you have any allergies

How do I prepare for my bariatric surgery? 

You are an important member of your own healthcare team. The steps you take before surgery can improve your comfort and outcome. You can prepare yourself for bariatric surgery by:

  • Answering all questions about your medical history and medications. This includes prescriptions, over-the-counter drugs, herbal treatments, and vitamins. It is a good idea to carry a current list of your medical conditions, medications, and allergies at all times.

  • Getting preoperative testing as directed. Testing will vary depending on your age, health, and specific procedure. Pre-operative testing may include a chest X-ray, EKG (electrocardiogram), blood tests, and other tests as needed.

  • Not eating or drinking before surgery as directed. Your surgery may be cancelled if you eat or drink too close to the start of surgery because you can choke on stomach contents during anesthesia.

  • Stopping smoking as soon as possible. Even quitting for just a few days can be beneficial and help the healing process.

  • Taking or stopping medications exactly as directed. This may include not taking aspirin, ibuprofen (Advil, Motrin), and blood thinners. 

Questions to ask your doctor

Facing surgery can be stressful. It is common for patients to forget some of their questions during a brief doctor’s office visit. You may also think of other questions after your appointment. Contact your doctor with concerns and questions before surgery and between appointments.

It is also a good idea to bring a list of questions to your pre-operative appointments. Questions can include:

  • Why do I need bariatric surgery? Are there any other options for treating my condition?

  • What type of bariatric surgery procedure will I need?

  • How long will the procedure take? When can I go home?

  • What kind of restrictions will I have after the surgery? When can I return to work and other activities?

  • What kind of assistance will I need at home?

  • How should I take my medications and supplements? 

  • What is the diet plan that I need to follow after surgery?

  • How will you treat my pain?

  • When should I follow-up with you?

  • How should I contact you?  Ask for numbers to call during and after regular hours.

What can I expect after my bariatric surgery?

Knowing what to expect can help make your road to recovery after gastric bypass surgery as smooth as possible. Bariatric surgery results vary depending on the specific surgery and other factors. For example:

  • Adjustable gastric banding (AGB, Lap-Band surgery, gastric band surgery) generally has a high weight-loss rate initially, but some people do not maintain long-term weight loss. The stomach and small intestine still function normally, reducing the risk of poor nutrition that can occur with malabsorptive (gastric bypass) procedures. You will need to see your surgeon regularly to adjust the gastric band. This is typically done in the doctor’s office.

  • Biliopancreatic diversion with a duodenal switch (BPD-DS) can result in weight loss that lasts longer than some other procedures. Risks include vitamin and mineral deficiencies that require ongoing nutritional supplementation. If deficiencies are not treated, they can lead to long-term complications, such as osteoporosis and anemia.

  • Roux-en-Y gastric bypass (RYGB) helps most people to lose weight quickly and successfully. Risks include vitamin and mineral deficiencies that require ongoing nutritional supplementation and a high-protein diet. If deficiencies are not treated, they can lead to long-term complications, such as osteoporosis and anemia.

  • Vertical sleeve gastrectomy (VSG, gastric sleeve surgery, gastric sleeve resection, tube gastrectomy) generally controls hunger better than other restrictive procedures. In addition, the stomach and small intestine still function normally, reducing the risk of poor nutrition.

How long will it take to recover?

You will stay briefly in the recovery room after surgery until you are alert, breathing effectively, and your vital signs are stable

You may have a sore throat if a tube was placed in your windpipe during surgery. This is usually temporary, but tell your care team if you are uncomfortable. You may have a tube that was passed through your nose into your stomach during surgery. This tube keeps your stomach empty. Your surgeon will remove the tube when your stomach has recovered enough to work properly. The tube is generally removed within 24 hours. 

Bariatric surgery generally requires a three to five-day hospital stay. Full recovery is a gradual process. Recovery time varies depending on the procedure, your general health, age, and other factors. 

Will I feel pain?

Pain control is important for healing and a smooth recovery. There will be some discomfort after your surgery. Your doctor will treat your pain so you are comfortable and can get the rest you need. Call your doctor if your pain gets worse or changes in any way because it may be a sign of a complication.

You will likely take narcotics for pain. Narcotics will make you feel drowsy. You should not drive while taking narcotics. 

When should I call my doctor?

It is important to keep your follow-up appointments after bariatric surgery. Contact your doctor for questions and concerns between appointments. Call your doctor right away or seek immediate medical care if you have:

How might bariatric surgery affect my everyday life?

Bariatric surgery is not a quick or easy fix for obesity. It is only one part of a complex treatment plan that includes a lifelong commitment to healthy dietary and exercise habits, vitamin supplementation, and regular follow-up care. 

Your diet will change drastically after bariatric surgery. Your surgeon will give you specific instructions about your diet and activity restrictions. Bariatric diets generally start with very small amounts of liquids and then gradually progress to small amounts of pureed and soft foods. You will transition to solid foods at about 10 to 12 weeks after your surgery.

Bariatric surgery can also cause other significant changes that may affect your everyday life including:

  • Change of body image

  • Changes in social, work and family relationships. As you lose weight, you will probably have an increase in energy and ability to participate in everyday activities, sports, exercise, social activities, and work

  • Chronic diarrhea may occur in some cases

  • Decreased risk of developing heart disease and its complications 

  • Improved quality of life 

  • Improvement or resolution of many diseases and conditions. These include migraines, depression, type 2 diabetes, metabolic syndrome, polycystic ovarian syndrome, venous stasis disease, gastroesophageal reflux disease (GERD), hypertension, stress urinary incontinence, gout, and high cholesterol.

  • Medications that were prescribed for diabetes or hypertension will be decreased or stopped as you lose weight. It is important to see your doctor regularly so these medications can be adjusted as needed.

Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Oct 30
View All Weight Loss Surgery Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Bariatric Surgery. The Journal of the American Medical Association.
  2. Bariatric Surgery - Following Doctor's Orders Results In 35% More Weight Loss. Medical News Today.
  3. Bariatric Surgery for Severe Obesity. National Institute of Diabetes and Digestive and Kidney diseases (NIDDK).
  4. Benefits of Bariatric Surgery. American Society for Metabolic & Bariatric Surgery.
  5. Pile, JC. Evaluating postoperative fever: A focused approach. Cleveland Clinic Journal of Medicine. 2006;73 (Suppl 1):S62.
  6. Poirier P, et al. Bariatric Surgery and Cardiovascular Risk Factors: A Scientific Statement from the American Heart Association. Circulation. 2011; 123: 1683-1701.
  7. Weight Loss Surgery.