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Gastric Bypass Surgery


Gastric bypass is a surgery that’s done to help you lose weight when most other methods have failed. It’s the most common type of bariatric or weight loss surgery.

This type of surgery is recommended for patients who have not been successful in losing weight using more conventional means such as dieting and exercise and/or when the person’s health in danger because of the excessive weight.

The surgery works by making your stomach smaller so that you won’t be able to eat as much food and take in as many calories as before. You’ll feel fuller faster and stop eating sooner, which should allow you to lose significant weight.

Candidates for Gastric Bypass Surgery

Gastric bypass can improve both the quality of life and the appearance of severely overweight or obese people. It can also reduce or eliminate serious health problems that tend to affect those who are overweight, including:

  • decreased mobility
  • type 2 diabetes
  • heart and circulation problems
  • sleep apnea (abnormal pauses in breathing during sleep)
  • high blood pressure
  • high cholesterol
  • severe gastroesophageal reflux (stomach contents going into the esophagus)
  • stroke

You may need to meet certain medical and lifestyle requirements to qualify for gastric bypass. Your doctor will perform an extensive screening process. You will also need to commit to making healthier lifestyle and dietary choices. Generally, people with extreme obesity (a body mass index (BMI) of 40 or more), those with obesity (a BMI of 35 to 39.9), and those with serious weight-related health problems may qualify.

How Gastric Bypass Surgery Works

Gastric bypass can be performed in two ways.

The most common procedure is laparoscopy. This procedure is done by the surgeon making several small incisions in your belly and passing a laparoscope (a small tube device with a camera connected to a video monitor) inside one opening. The surgeon uses thin surgical instruments inserted in the other openings to perform the surgery while looking at the monitor to see inside your belly. This method has a quicker recovery time and causes less scarring than an open surigical procedure where the abdominal wall is opened.

However, laparoscopy may not be right for people who:

  • have had previous abdominal surgery (scarring may prevent laparoscope/tools entry)
  • have severe heart or lung disease (more controlled heart/lung monitoring required)
  • weigh more than 350 lbs. (laparoscopic entry and visualization may be compromised)

If laparoscopy is not possible, an open or traditional surgery is performed. The surgeon makes a large incision in the belly and directly accesses your stomach and small intestines to perform the bypass surgery.

In both types of surgery, a large portion of the stomach and the firs part of the small intestine are bypassed so that you can only take in a small amount of food. There are a number of surgical bypass procedures that can be done.

One of the more common is when staples are used to divide your stomach into a small upper section, called the pouch, and a larger bottom section. The pouch is where the food you eat will now be stored. It is the size of a walnut and only holds about one ounce of food.

During the next step of the gastric bypass, the surgeon connects a part of the second part of your small intestine, called the jejunum, to a small hole in the pouch. This allows the food you eat to travel from the pouch directly into the small intestine. This bypass allows your body to only accept a small amount of food at a time and to absorb fewer calories.

The procedure takes between one and four hours, depending on the type of surgery.Is performed.

Risks of Gastric Bypass Surgery

All surgeries carry risks of complications. Some may be usual complications for any invasive procedure, while others are rare. And some can be serious. In the case of bypass surgery, these include an allergic reaction to the anesthesia, blood loss, infection, and blood clots. Specific complications that can occur with gastric bypass surgery are:

  • injury to the stomach, intestines, or other organs
  • food leakage through the staples after surgery (emergency follow-up surgery may be required)

Over time, other serious complications from gastric bypass surgery may occur, including:

  • the pouch breaking apart, which requires surgery to repair it
  • narrowing of the opening between your stomach pouch and the small intestine, requiring further surgery
  • gastritis (inflammation of stomach lining)
  • vomiting from eating more than your stomach pouch can hold (a common side effect of the procedure)
  • gallstones and gallbladder attacks from losing weight quickly
  • kidney stones
  • hernia (more common from open surgery)
  • heartburn
  • stomach ulcers

Rarely, this procedure can result in your body receiving fewer nutrients than it needs. Risks related to poor nutrition include:

  • anemia from low iron or vitamin B12 levels
  • low calcium levels, which can cause osteoporosis (a condition that causes your bones to become weak and to break easily)
  • dumping syndrome (the contents of your stomach move through your small intestine too quickly, causing discomfort and poor nutritional absorption)

Outlook for Long-Term Weight Loss

Gastric bypass is not an easy weight loss fix. You still need to exercise and eat a healthy diet. You may have to work with a nutritionist to help you adapt to your new eating plan. Most people lose 10 to 20 pounds per month in the first year after surgery. Those who exercise and stick to their eating plans lose the most weight. Weight loss will taper off gradually.

Most patients see significant improvement in their weight-related health problems like diabetes, mobility issues, and high cholesterol, and are at a lower risk for heart disease and stroke.

Content licensed from:

Written by: Michael Kerr
Medically reviewed : Brenda B. Spriggs, MD, MPH, FACP

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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