Gastric banding is a form of obesity surgery, which is the last resort when all other attempts at weight loss have failed.
Obesity is a genetically based disease where sufferers have a strong desire to consume more food than they need. Obesity surgery doesn't cure this, but can go a long way to controlling this hunger and helping the sufferer gain control of their weight.
Gastric stapling and gastric banding involve procedures where part of the stomach is sectioned off at the top of the stomach. This allows only a small amount of food to be consumed at a sitting. This results in a feeling of satisfaction and the loss of hunger after a small, solid meal is eaten. If more food is eaten in the next hour or two, an overfull and bloated feeling will be experienced and regurgitation may occur.
Stomach stapling is usually done through a cut in the stomach, while banding can usually be done with laparoscopic or 'keyhole' surgery. Banding has the advantage that it can be 'adjusted'. If there are problems with eating, the band can be loosened by an injection through the abdominal wall or, if insufficient weight is lost, the band can be tightened.
Both operations may result in early complications (such as infection, leakage from the stomach, thrombosis or embolism, or even death), although these are uncommon. In the longer term, staple lines can break down or the band may slip or become infected. Both operations are reversible.
Another surgical option is a bowel bypass that reduces the length of the small intestine where most food nutrients are of it is absorbed thereby limiting the body's ability to absorb nutrients. They're not frequently performed and are major operations.