Gastric Bypass (Gastric Banding)


The gastric bypass is carried out in the following way. A surgeon creates a small pouch from the lesser curvature of the stomach. It is the size of a thumb. It encloses approximately 400 mL of storage. Therefore, with only this amount of food storage space in the stomach an individual can easily achieve weight loss.


A stomach can simply be divided or partitioned by the help of staples. It is must to do a total division to lower the risk of fistula formation as sometimes two stomach sections may joined and healed together. The other process involved is the re-construction of the gastrointestinal tract that allows drainage of both parts of the stomach. There are various techniques for this and these also alter the food absorption and nutritional status.

Different Gastric Bypass Reconstructive Procedures

Roux en-Y

The most commonly used gastric bypass reconstructive surgery is named as Roux-en-y. It can be done proximally or distally. This is a laparoscopic procedure but it can also be carried out via a laparotomy. In proximal procedure the small intestine is incised about 45 cm below the inferior part of the stomach and is reorganized into a Y-configuration. This configuration enables steady food flow from the small upper stomach pocket through a Roux limb. In distal procedure the Y-connection is created much nearer to the distal end of the small intestine. This can reduce the malabsorption.

Mini-Gastric Bypass (MGB)

In the Mini gastric bypass a long tube is formed along the lesser curvature of the stomach. The loop of the small intestine is joined to this tube at some distance from the ligament of Treitz. It has been found out in extensive research that a mini gastric bypass is safer procedure than other weight loss surgical options. It is an alternative procedure to the Roux en-Y gastric bypass. There are low risks of complications associated with it.

Risks & Complications

There are many risks and complications associated with the gastric bypass. Mortality is also found with this procedure but the rate is very low and depends on the presence of disease such as heart disease, pulmonary embolism, sleep apnoea or diabetes. Other complications are as follows:

Medical complications: These are related to the medicines or anaesthesia used in performing the surgery. These include:

  • Hypersensitivity reaction
  • Bleeding/haemorrhage
  • Risks of heart attack, renal failure and other cardiovascular disorders

Specific Risks and Complication of Gastric Bypass: These are usually due to surgical procedure and include:

  • Deep venous thrombosis formation
  • Infection at the site of incisions
  • Leakage of gastric contents though the staple: This leakage then serves as a source of infection and can lead to serious consequences.
  • Risk of abdominal hernia
  • Nutritional deficiencies
  • Bowel obstruction is also seen here due to adhesion formation
  • Anastomotic ulcer: It may occur in a few people due to poor blood supply to the area of anastomosis, gastric acid secretion, or due to infection by Helicobacter pylori bacteria.
  • Dumping Syndrome: This syndrome is also seen after the gastric bypass procedure. It is characterized by the nausea, diarrhoea and reflux.  It takes place when a person eats a sugar containing food.
Q. When is gastric bypass regarded as successful?

A. Gastric bypass is regarded successful when it enables a person to lose about 50 percent of their body weight. It’s vital to bear in mind that there are no assurances with any surgical procedure of weight loss.

Q. What are the restrictions related to diet after the weight loss surgery?

A. After the surgery, you will be directed about your food intake, depending on your body needs. Registered dieticians will provide you dietary education prior to and following surgery.

Q. Is it possible to get back the weight again?

A. It is possible as gastric bypass is not a curable procedure. It therefore requires that you stay away from fat-causing foods such as carbonated and caffeinated beverages, fast or junk foods etc.

Q. What will happen to the portion of the stomach that is unused?

A. The dormant segment of the stomach will continue to carry on its function of producing gastric enzymes and acids. It won’t impact your health in a negative sense.

Q. What are the activities that should be restricted following gastric bypass?

A. Strenuous activities are usually restricted after surgery. You are recommended not to drive if you are using any painkillers of a sedative nature.