Bariatric Surgery: Everything You Need to Know

bariatric doctor and obese patient
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Bariatric medicine includes weight-loss surgery that reduces the amount of food your body can absorb. A number of different procedures are defined as bariatric operations. Bariatric surgery is part of a multidisciplinary medical bariatrics program that includes healthy eating, exercise, and treatment of conditions like type 2 diabetes or thyroid disease. Typically, a bariatric doctor performs surgery to help you avoid health complications of obesity, not for cosmetic reasons. Surgical preparation involves imaging tests and blood tests, and recovery takes several months.

What Is Bariatric Surgery?

Bariatric surgery reduces the amount of food you can eat and absorb by shrinking the stomach. There are several ways this can be done, including removing part of the stomach, placing a band around the stomach, and gastric bypass, in which the opening between the stomach and the small intestine is relocated.

This surgery can be done as a laparotomy (open abdominal procedure with a large incision) or laparoscopically (minimally invasive camera assisted abdominal procedure with a small incision). General anesthesia is required for pain control during a bariatric operation. You may need to stay overnight in the hospital for several days after your surgery.

Surgical options:

  • Gastric balloon placement: A deflated balloon is inserted inside the stomach, and then inflated to reduce the space inside the stomach. This is typically done with a minimally invasive technique.
  • Adjustable gastric banding: Also known as a lap band, gastric banding is the placement of a non-permanent silicone band around the stomach. The band reduces the size of the stomach without cutting away any portion of the stomach. This procedure is usually performed laparoscopically.
  • Vertical banded gastroplasty: Sometimes described as stomach stapling or the Mason procedure, this procedure is done to shrink the stomach size with surgical staples that create a smaller stomach pouch.
  • Sleeve gastrectomy: A gastric sleeve surgery is the removal of a portion of the stomach, resulting in a reduction of the stomach's size. After this procedure, the remaining stomach is shaped like a sleeve.
  • Gastric bypass surgery: Gastric bypass surgery is detachment of the opening of the small intestine from the lower part of the stomach and reattachment of the opening of the small intestine to the upper part of the stomach. This decreases the amount of food the stomach can hold. The most common gastric bypass procedure, the Roux-en-Y bypass, includes cutting away a portion of the stomach in addition to the bypass portion of the surgery.


Bariatric surgery is a major procedure. You might not be a candidate for this surgery if you have a severe heart or lung disease that could make it risky for you to have surgery and general anesthesia.

A history of multiple abdominal surgeries can complicate surgery if issues like adhesions (scar tissue) have developed.

Sometimes obesity or excess weight can be caused by factors such as medication or medical conditions. And eating disorders can be associated with obesity. In these situations, bariatric surgery might not be effective, and other treatments would be considered instead.

Potential Risks

In addition to the risks of general anesthesia and abdominal surgery, there are a number of potential adverse effects specific to bariatric surgery.

  • Surgical complications include bleeding or stomach or intestinal perforation. These are life-threatening emergencies that require immediate intervention.
  • An infection or inflammation can develop in the days or weeks after surgery. These issues can cause pain or bowel obstruction that requires medical and/or surgical management.
  • Often, severe weight loss can occur in the months after bariatric surgery. This can cause malnutrition, dumping syndrome, and adrenal failure. Over time, these issues can resolve, but medical treatment is typically required.
  • Nutrient deficiency can persist permanently, requiring nutritional supplementation.
  • Sometimes an incisional hernia (a defect in the abdominal wall) or adhesions can form after bariatric surgery, and this may cause pain or bowel obstruction at a later time.

Purpose of Bariatric Surgery

Bariatric surgery is designed to reduce the number of calories absorbed by the body for the purpose of weight loss. Weight loss is a way of reversing and preventing complications of obesity.

Bariatric surgery may be considered if you have a body mass index (BMI) greater than or equal to 40, or if you are more than 100 pounds overweight, or if you have a BMI of 35 or more with complications of obesity.

Early interventions for managing excess weight may include diets, structured exercise programs, and intensive behavioral therapies to target and fix unhealthy eating habits. When these non-surgical strategies are not effective, bariatric surgery is often considered.

Bariatric surgery can help treat and reduce the risk of:

Some of the late-stage complications of these conditions can complicate bariatric surgery, so the procedure is generally safer before severe health consequences of obesity arise.

How to Prepare

Preparation for bariatric surgery involves imaging tests, like an abdominal ultrasound or computerized tomography (CT) that can help your surgeon plan out your procedure. If you have any structural abnormalities, such as an ulcer or a polyp, it might impact the approach that your surgeon will use.

Your doctor will describe the type of procedure that you will have, the location and size of the scar you should expect, and the effects and side effects you should anticipate after your surgery.

Obesity can be associated with medical problems, so you will need to have a complete blood count (CBC), liver function tests, and blood chemistry tests. While abnormalities in these tests probably won't contraindicate surgery, issues like anemia (low red blood cells), or low calcium would need to be corrected prior to your surgery.

Additionally, you will need to have a chest X-ray and electrocardiogram (EKG) for pre-surgical anesthesia testing.

You may also need to have some of your own blood collected and stored prior to your operation in case you would need a blood transfusion during surgery.


You will have your surgery in an operating room that's located either in a hospital or a surgical center.

What to Wear

You can wear anything comfortable to your surgery appointment. You will wear a surgical gown during your surgery.

Your abdomen will be sensitive and might be sore after surgery. And, when you go home after surgery, you might have a surgical drain in place. So you should have something to wear that is loose and that allows access to the drain. A dress or tight pants can be problematic.

Food and Drink

You will need to abstain from eating and drinking starting at midnight the night before your surgery.


Your doctor will give you specific instructions regarding medication. You might be given an adjusted prescription dose if you take steroids or medication for diabetes.

And you might be advised to stop or reduce the dose of any blood thinners you take for several days before your surgery.

What to Bring

You need to make sure that you have personal identification, health insurance information, and a form of payment for any portion of your surgery that you will be responsible for. You should also have a list of your medications and doses with you.

You will need to have someone drive you home when you are discharged from the hospital after your surgery.

Pre-Op Lifestyle Changes

You might have a special diet in the months prior to your surgery. Generally, following a nutritional plan and achieving a target weight loss are recommended prior to bariatric surgery.

What to Expect on the Day of Surgery

When you go to your surgery appointment, you need to register and sign a consent form. You will go to a pre-operative area, where you might have some same-day tests, such as CBC, blood chemistry tests, and a urine test.

You will have an intravenous (IV, in a vein) line placed in your arm or hand. Your temperature, blood pressure, pulse, respiratory rate, and blood oxygen level will be monitored.

Your surgeon and anesthesiologist may come to see you before you go to the operating room.

Before the Surgery

You will have your anesthesia started and your skin prepared before your surgery. You will also have a urinary catheter placed.

You will have a surgical drape placed over your body, and the area of skin on your abdomen where you will have your incision will be exposed and cleaned with a surgical solution.

Your anesthesia will begin as the anesthetic medication is injected into your IV. This medication will prevent pain, paralyze your muscles, and put you to sleep. You will have a breathing tube placed into your throat for respiratory assistance during your surgery.

During the Surgery

Your surgeon will begin your procedure by making an incision in your skin.

If you are having an open laparotomy, you will have a large incision that gives your surgeon access to your stomach and possibly your small intestine as well. The size and location of your incision for an open laparotomy depend on the exact procedure you are having.

And if you are having a minimally invasive laparoscopic procedure, you will have one or two small abdominal incisions, which can be approximately one or two inches in length each. A laparoscope, which is a camera-equipped surgical device, is inserted into your abdomen.

After your skin is cut, you will have an incision into your mesothelium. This is a protective covering under your skin that encloses your abdominal organs. Your surgeon will then have access to your stomach and the surrounding area.

The next steps of your surgery can vary, depending on exactly which type of bariatric procedure you are having.

Steps in your bariatric surgery can include:

  • Placement of a balloon in your stomach
  • Placement of a band around your stomach
  • Stapling of your stomach to decrease the size
  • Resection of part of your stomach, and closing the stomach with sutures to prevent leaking of stomach contents
  • Cutting the opening of the intestine away from the stomach opening, and surgically repositioning it to a new opening higher in the stomach

A combination of these steps may be done. Throughout surgery, bleeding is controlled, and excess blood and fluid are suctioned. If necessary, a blood transfusion might be done during surgery to replace the loss of blood.

After the structure of your stomach and small intestine are optimally positioned and any incisions in your stomach and intestines are closed, your surgeon will also close any incisions that were made in your mesothelium.

A temporary drain may be placed in your stomach, with the tube extending to the outside of your body for external collection of inflammatory fluid. The drain may remain in place until the inflammation subsides, possibly several weeks after surgery

Your skin incision will be closed, and the surgical wound will be covered with surgical dressing.

Your anesthesia will be stopped, your breathing tube removed, and your anesthesia team will see that you are breathing independently before taking you to the surgical recovery area.

After the Surgery

In the recovery area, you will continue to have your blood pressure, pulse, respiratory rate, and oxygen saturation monitored. Additionally, your surgical wound may be checked. And if you have a drain, the fluid in the drain will be observed and emptied. You may receive pain medication.

You will have your urinary catheter removed and you will be able to use the toilet or a bedpan with assistance.

You will likely stay in the hospital for several days after your bariatric surgery. During your stay, you should gradually be able to get up and walk on your own and use the toilet on your own.

While in the hospital, you will learn how to manage your drain if you have one.

During your hospital stay, you should be able to drink clear fluids, and you might advance to thicker fluids or solids.

Advancing your diet will take place more quickly if you've had a band or ballon placed, and more gradually if you've had any part of your stomach or intestines cut. As you are advancing your diet, you will also likely need to have IV fluid supplementation in the first few days after your surgery.

Your surgical team will also want to ensure that you are able to pass stool before you leave the hospital. Being unable to pass stool after bariatric surgery is a sign of stomach or intestinal blockage.

Once you are ready to leave the hospital, you will receive instructions about at-home pain management, diet, activity restrictions, follow up appointments, and signs of complications to look out for.


Because there are several different types of bariatric procedures, your recovery can vary. The recovery time is longer if you have had part of your stomach or small intestine cut.

You will see your doctor for a follow-up appointment within days after your discharge from the hospital, and again every few weeks for several months. During these visits, you will have your drain and stitches removed, your wound inspected, and your surgical dressing changed.

After any bariatric procedure, you can have abdominal pain and cramping and you won't feel like you can tolerate food and liquids right away. You need to gradually increase your food and drink intake.

And you need to follow instructions regarding wound and drain care and watch out for complications. You might also have restrictions on your physical activity for several weeks.


As you are healing in the first few weeks after surgery, you need to keep your surgical wound clean and dry. You should change your dressing and care for your drain as directed.

Signs of complications to look out for include:

  • Fever
  • Severe or worsening pain
  • Seeping of blood or pus from the wound or in the drain
  • Tenderness, redness, or swelling around the wound that's getting worse
  • Vomiting or hematemesis (vomiting blood)
  • Inability to pass stool
  • Severe diarrhea or blood in the stool

If you experience any of these signs, be sure to call your surgeon's office.

Coping With Recovery

As you are recovering, you may have some pain. You should take your pain medication and any other prescriptions you received as directed.

You may have some restrictions on your activity, but you also need to move around so you can avoid issues like blood clots and pneumonia that can occur due to inactivity.

You can also feel full or bloated after eating and drinking small amounts. This is expected, and this feeling is part of the purpose of your surgery. However, the discomfort may come as a surprise.

You will need to work with your medical team as you learn to adjust to your changed tolerance for food. Often, it is recommended to eat small amounts of food more frequently and to avoid food that doesn't provide the nutrients you need.

Long Term Care

You will need to follow up with your doctor to ensure that you are healing well and that you are getting the nutrition you need.

You may need periodic blood tests to ensure that you aren't missing out on nutrients, and you might receive a prescription for a vitamin, like vitamin D, or a mineral, like calcium or magnesium if your tests show that you have a deficiency.

Some nutrients, such as vitamin B12, might not be well absorbed after bariatric surgery, so you may need IV supplementation.

Possible Future Surgeries

Generally, bariatric surgery is a single procedure that's not meant to be followed up with additional procedures.

If you develop adhesions due to your bariatric procedure, it could cause bowel obstruction years later, and the treatment for the bowel obstruction and adhesion resection can include surgery.

Lifestyle Adjustment

After having bariatric surgery, you'll have to incorporate a healthy diet and exercise into your life to maintain your weight and avoid malnutrition.

Sometimes people overeat, even after bariatric surgery. Chronic overeating can stretch the stomach and cause it to enlarge again, potentially canceling out the benefits of the surgery.

You will likely receive guidance from a nutritionist or a dietitian regarding the amount and type of food you should eat to maintain your health.

A Word From Verywell

Bariatric surgery is an option that can help achieve weight loss. There are lasting health benefits of bariatric surgery, but there are also long term lifestyle adjustments that you have to make to maintain the benefits.

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