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 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).
During this procedure, the surgeon creates a small, sleeve-shaped stomach. It is larger than the stomach pouch created during Roux-en-Y bypass—and is about the size of a banana.
It generates weight loss by restricting the amount of food (and therefore calories) that can be eaten by removing 85% or more of the stomach without bypassing the intestines or causing any gastrointestinal malabsorption.
Reduces stomach capacity but tends to allow the stomach to function normally so most food items can be consumed, albeit in small amounts.
Adjustable Gastric Band
A gastric band procedure is a restrictive laparoscopic surgical procedure in which a band is placed around the upper most part of the stomach. This band divides the stomach into two portions, one small and one large portion. Because food is regulated, most patients feel full faster.
Food digestion occurs through the normal digestive and absorption process.
Laparoscopic adjustable gastric banding leads to loss of about 40% of excess weight, on average.
Gastric banding is considered the least invasive weight loss surgery; it is also the safest.
Unlike gastric bypass surgery, gastric banding does not interfere with food absorption. For this reason, vitamin deficiencies are rare after gastric banding.