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What Happens in Gastric Bypass Surgery?

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What Happens in Gastric Bypass Surgery?

There are two goals for gastric bypass surgery: first, a small pouch is made in the stomach that will restrict the amount of food intake, food intake; and then bypasses are formed to cause malabsorption of calories and other food nutrients in the duodenum and other segments of the small intestine.

Types of Gastric Bypass Surgery

Roux-en-Y gastric bypass (RGB): This is the most commonly performed type of gastric bypass surgery in the United States. In this procedure, a small pouch is formed in the top portion of the stomach by inserting vertical bands or by stapling sections of the stomach together. As a result, the patient will feel less hungry and will eat less. Next, a Y-shaped portion of the small intestine is connected to this pouch, which will allow food to bypass the duodenum and part of the jejunum. This causes a reduction in the absorption of calories and nutrients.

Some surgeons do this surgery with a laparoscope, which enables them to view the inside of the abdomen with this camera-like device. This type of surgery uses small incisions, and the recovery time is limited compared to other types of weight loss surgery.

Extensive gastric bypass: This is the more complex version of gastric bypass surgery, in which the lower segment of the stomach is removed. What remains is a small pouch that is attached to the last segment of the small intestine, with the duodenum and the jejunum bypassed completely. This procedure does aid in helping patients to achieve significant weight loss, but it is used less often than other types of surgery because it involves a high risk for nutritional deficiencies.

People who have bypass surgery generally lose two-thirds of their excess weight within two years.

Risks and Side Effects of Gastric Bypass Surgery

People who undergo gastric bypass surgery are at risk for a range of complications, such as:

  • Pouch stretching (when the stomach stretches back to its original size
  • Band erosion (when the band used to close off part of the stomach disintegrates).
  • Erosion of staple lines (when the vertical band and staples fall apart, thus causing the procedure to be reversed).
  • Leaking of stomach contents into the abdomen (a potentially dangerous side effect, because stomach acid can damage other organs).
  • Various nutritional deficiencies, which can lead to significant health problems.

There is another complication that can result from gastric bypass surgery known as the “dumping syndrome,” in which stomach contents move far too quickly through the small intestine. When this happens, patients can experience nausea, fatigue, heavy sweating, and diarrhea after meals. Also, rapid weight loss can cause gallstones, but medication can be used to dissolve them.

Risks Caused by Nutritional Deficiencies

In general, the more extensive the gastric bypass surgery, the greater the risk for complications and nutritional deficiencies.

Anemia can result from the limited absorption of vitamin B-12 and iron. And the lack of calcium absorption can trigger osteoporosis. It is essential for people who have gastric bypass surgery to take daily nutritional supplements, which usually can ward off such deficiencies.