Your Anatomy

When you eat or drink before surgery, food travels down your esophagus into your stomach, which can stretch to about the size of a football. From there, it passes into the first part of the small intestine, the duodenum. Many vitamins and minerals, as well as some carbohydrates are absorbed in the duodenum. Next food moves into the rest of the small intestine where most of the absorption takes place before moving to the colon, or large intestine, before being excreted.

The Procedures

1.) Gastric Bypass
For the gastric bypass, a small, 1-ounce pouch is created at the top of the stomach, completely separate from the larger stomach remaining. The pouch can only stretch to the size of a small lemon. The small pouch releases food slowly into your digestive system, resulting in the sensation of fullness with very little food intake. The new opening to your small intestine from your stomach is called a stoma. It is very small, about as big as the end of your pinky finger or nostril. Everything you eat after surgery must be able to fit through that hole.

The next step in the surgery is to divide and then reattach the small intestine. Bypassing part of the intestine creates malabsorption, which further reduces calories and promotes weight loss.

2.) Adjustable Gastric Banding
Adjustable gastric banding is a purely restrictive procedure that involves “cinching” off the top of the stomach to form a small (approximately two-ounce) pouch. The band is inserted laparoscopically, so the surgery is minimally invasive. Patients then feel full on small amounts of food. The small intestines are not rerouted so, unlike bypass surgery, there is no impaired absorption of nutrients (malabsorption). That means the recommended vitamin/mineral supplementation is much less and no dumping syndrome develops (when concentrated sweets or other foods cause diarrhea, nausea and weakness).

Why they work

The gastric bypass is considered the gold standard of weight loss surgeries for two reasons. It is restrictive, meaning you simply can't put much food in your pouch and it is malabsorptive, meaning you don't absorb as many calories because the duodenum is bypassed. Weight loss results when you consume fewer calories than the body burns. If you eat more calories than your body needs and don't exercise, you gain weight.

Weight loss with the adjustable gastric banding is much slower, about 1-3 lbs/week. However, unlike the bypass, the band can be adjusted and weight loss can continue indefinitely. The band can be loosened for pregnancy or during illness and then tightened again when weight loss can continue. At the 5-year point, patients can lose the same amount of weight with either procedure.

Success

Studies show that virtually all patients undergoing the gastric bypass experience significant relief from obesity-related conditions such as diabetes, hypertension, arthritis, reflux and sleep apnea. Typically, 50-60% of excess weight is kept off even after 5 years. Long-term research shows that satisfaction with the procedure is directly related to the amount of weight lost. The patient's commitment to maintaining new diet and exercise behaviors is crucial for success. The surgery is one tool to help reach a healthy weight and lifestyle.

With the adjustable gastric banding, patients also can lose 54-75% of excess body weight and can show significant improvement in related diseases such as reflux, heart disease, high blood pressure, diabetes and sleep apnea.