How Gastric Bypass works?

Gastric Bypass is a restrictive and malabsorptive procedure that has been performed worldwide for over 35 years. Gastric bypass involves cutting and stapling a small piece of the stomach so that it becomes separate from the other portion.

This area acts as a new, smaller stomach with the rest being restricted permanently. The top of the small intestine is then severed completely with the stapling device with the ends of the intestine routed to the smaller stomach pouch. The other end is attached to the small intestine so that the digestive liquids from the liver, gallbladder, duodenum and pancreas can process food.

Gastric bypass surgery makes the stomach smaller and allows food to bypass part of the small intestine. You will feel full more quickly than when your stomach was its original size, which reduces the amount of food you eat and thus the calories consumed. Bypassing part of the intestine also results in fewer calories being absorbed. This leads to weight loss.

The most common gastric bypass surgery is a Roux-en-Y gastric bypass.

In normal digestion, food passes through the stomach and enters the small intestine, where most of the nutrients and calories are absorbed. It then passes into the large intestine (colon), and the remaining waste is eventually excreted.

In a Roux-en-Y gastric bypass, the stomach is made smaller by creating a small pouch at the top of the stomach using surgical staples or a plastic band. The smaller stomach is connected directly to the middle portion of the small intestine (jejunum), bypassing the rest of the stomach and the upper portion of the small intestine (duodenum).

This procedure can be done by making a large incision in the abdomen (an open procedure) or by making five small incisions and using long instruments and a camera to guide the surgery (laparoscopic approach).

Advantages of the Gastric Bypass Roux-en-Y Procedure

• Average excess weight loss is usually higher than with purely restrictive procedures.
• One year after surgery, weight loss can average 77% of excess body weight. After 10 to 14 years, some patients have maintained 50-60% of excess body weight loss.
• 96% of certain associated health conditions (back pain, sleep apnea, high blood pressure, diabetes and depression) were improved or resolved according to a 2000 study of 500 patients.

Risks Specific to the Gastric Bypass Roux-en-Y Procedure

• "Dumping syndrome." When stomach contents are literally "dumped" rapidly into the small intestine. Sometimes triggered by too much sugar or large amounts of food. Dumping syndrome doesn't pose a health risk, but its symptoms aren't fun: nausea, weakness, sweating, faintness, and diarrhea. Some patients can prevent dumping syndrome by avoiding sweets after surgery.
• Up to 20% of patients need follow-up operations to correct problems like hernias.
• Up to 30% of patients develop gallstones after losing weight. You can reduce the risk of gallstones by taking bile salts for 6 months following surgery.
• Leakage of the connection between the pouch and the intestine. This is very rare, but potentially dangerous.
• Diminished effectiveness. The success of the procedure can be reduced if the stomach pouch is stretched and/or left larger than 15-30cc (1/2 to one ounce).
• Poor views of internal organs. The bypassed portion of the stomach, duodenum, and segments of the small intestine are difficult to see using X-ray or endoscopy. This only becomes a problem if the patient develops ulcers, bleeding, or malignancy. Gastric bypass does not cause cancer.
• Nutrient deficiencies. Almost a third of patients develop nutritional deficiencies because the duodenum is bypassed in this procedure. So the body doesn't absorb iron, calcium and other nutrients efficiently after surgery. Fortunately, these deficiencies can usually be controlled with proper diet and vitamin supplements. Nutrient deficiencies can lead to:
• Iron deficiency anemia. Because the duodenum is bypassed in this procedure, the body doesn't absorb iron and calcium very well after surgery, which can lead to iron deficiency anemia. This is a particular concern for patients who experience chronic blood loss during menstruation or from bleeding hemorrhoids.
• Osteoporosis. Because the body doesn't absorb calcium properly after surgery, there is a greater risk of developing osteoporosis.
• Metabolic bone disease. Also caused by bypassing the duodenum, some patients experience bone pain, loss of height, humped back and fractures of the ribs and hip bones.
• Chronic anemia. A type of anemia caused by a deficiency of vitamin B12. Can usually be managed with pills or injections.

Is the Gastric Bypass Surgery Right for Me?

Although guidelines vary, surgery is generally considered when your body mass index is 40 or higher or you have a life-threatening or disabling condition related to your weight.

Your doctor may only consider doing gastric bypass surgery if you have not been able to lose weight with other treatments.

The following conditions may also be required or are at least considered:

• You have been obese for at least 5 years.
• You do not have an ongoing problem with alcohol.
• You do not have untreated depression or another major psychiatric disorder.
• You are between 18 and 65 years of age.

All surgeries have risk, and it is important for you and your health professional to discuss your treatment options to decide what is best for your situation.