Introduction
Gastric bypass surgery combines the creation of a small stomach pouch to restrict food intake and construction of bypasses of the duodenum and other segments of the small intestine to cause malabsorption (decreased ability to absorb calories and nutrients from food).
Types of Gastric Bypass Surgery
- Roux-en-Y gastric bypass (RGB): This operation is the most common gastric bypass surgery performed in the U.S. First, a small stomach pouch is created by stapling part of the stomach together or by vertical banding. This limits how much food you can eat. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the duodenum as well as the first portion of the jejunum. This causes reduced calorie and nutrient absorption. This procedure can now be done with a laparoscope (a thin telescope-like instrument for viewing inside the abdomen) in some people. This involves using small incisions and generally has a more rapid recovery time.
- Extensive gastric bypass (biliopancreatic diversion): In this more complicated gastric bypass operation, the lower portion of the stomach is removed. The small pouch that remains is connected directly to the final segment of the small intestine, thus completely bypassing both the duodenum and jejunum. Although this procedure successfully promotes weight loss, it is not as widely used because of the high risk for nutritional deficiencies.
Gastric bypass surgery that causes malabsorption and restricts food intake produces more weight loss than restriction operations like gastric banding, which only decrease food intake. People who have bypass surgery generally lose two-thirds of their excess weight within two years.
Life After Gastric Bypass Surgery
Medical Authors: Angela Generoso and
Laura Lee Bloor
Staff Writers, MedicineNet.com
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
As of July 14, 2008, Mara Owens has lost 132 pounds.
“I feel amazing; I feel really good about what I?ve done. It takes a while for you to wrap your head around not being as big [anymore]. I still think I won?t fit into that airline seat or [I?ll] take up too much room. But that will come,” she says.
At 5-foot-5, 272 pounds, Owens underwent gastric bypass surgery, a procedure in which part of her stomach was stapled down to create a small
pouch, limiting the amount of food she can eat. A Y-shaped part of the small
intestine was attached to the pouch, which lets food bypass the first part of the small
intestine and a section of the second part. This results in fewer
calories and nutrients taken in altogether.
Owens says her decision to undergo weight-loss surgery stemmed
from years of research after countless failed diets and exercise programs. She
felt she had tried everything that was reasonable in an effort to bring her
weight down.
“I didn’t have high blood pressure yet,” she says.
“I didn’t have diabetes yet. But if I didn’t do something soon, I would
have it.”
Read on as Mara awaits surgery »
Risks of Gastric Bypass Surgery
People who undergo gastric bypass surgery are at risk for:
- Pouch stretching (stomach gets bigger overtime, stretching back to its
original size). - Band erosion (the band closing off part of the stomach disintegrates).
- Breakdown of staple lines (band and staples fall apart, reversing the
procedure). - Leakage of stomach contents into the abdomen (this is dangerous because
the acid can eat away other organs). - Nutritional deficiencies causing health problems.
Gastric bypass surgery also may cause “dumping syndrome,” whereby stomach
contents move too rapidly through the small intestine. Symptoms include nausea,
weakness, sweating, faintness, and, occasionally, diarrhea after eating, as well
as the inability to eat sweets without becoming extremely weak. Gallstones can
occur in response to rapid weight loss. They can be dissolved with medication
taken after the surgery.
Complications From Nutritional Deficiencies
The limited absorption of vitamin B-12 and iron can cause anemia. The lack of
calcium absorption can cause osteoporosis and metabolic bone disease. People who
undergo this procedure are required to take nutritional supplements that usually
prevent these deficiencies.
The more extensive the gastric bypass surgery, the greater the risk for
complications and nutritional deficiencies. People who undergo extensive
bypasses of the normal digestive process require not only close monitoring, but
also lifelong use of special foods and medications.
WebMD Medical Reference