Gastric Bypass.Roux-en-Y gastric bypass, also called gastric bypass, helps you to lose weight by reducing the amount of food you can eat and reducing the number of calories and nutrients you absorb from the food you eat.

In recent years, better clinical understanding of procedures combining restrictive and malabsorptive approaches has increased the choices of effective bariatric surgery for thousands of patients. By adding malabsorption, food is delayed in mixing with bile and pancreatic juices that aid in the absorption of nutrients. The result can be an early sense of fullness, combined with a sense of satisfaction, which reduces the desire to eat.

The Roux-and-Y Gastric Bypass is considered by many to be the current gold standard procedure for bariatric surgery. It is the most frequently performed bariatric procedure in the United States. In this procedure, stapling creates a small (15 to 20 cc) stomach pouch. The outlet from this newly formed pouch empties directly into the lower portion of the jejunum, thus bypassing calorie absorption and the duodenum. This is done by dividing the small intestine just beyond the duodenum and constructing a connection with the new, smaller stomach pouch. The length of either segment of the intestine can be increased to produce lower or higher levels of malabsorption.


  • The average excess weight loss in the Roux-and-Y procedure is generally higher in a compliant patient than with purely restrictive procedures.
  • One year after surgery, weight loss can average 77% of excess body weight.
  • Studies show that after 10 to 14 years, 60% of excess body weight loss has been maintained by patients.
  • A 2004-meta-analysis of more than 22 000 patients showed that those who underwent a bariatric surgical procedure experienced a complete resolution or improvement of their co-morbid conditions including diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea.


(The following are in addition to the general risks of surgery)

  • Because the duodenum is bypassed, poor absorption of iron and calcium can result in the lowering of total body iron and predisposition to iron deficiency anemia. Women should be aware of the potential for heightened bone calcium loss.
  • Bypassing the duodenum has caused metabolic bone disease in some patients, resulting in bone pain, loss of height, humped back, and fractures of the ribs and hip bones. All of the deficiencies mentioned above, however, can be managed through proper diet and vitamin supplements.
  • Chronic anemia due to Vitamin B12 deficiency can occur. This can usually be managed with Vitamin B12 pills or injections.
  • When removing or bypassing the pylorus, a condition known as “dumping syndrome” can occur as the result of rapid emptying of stomach contents into the small intestine. This is sometimes triggered when too much sugar or large amounts of food are consumed. While generally not considered to be a serious risk to your health, the results can be extremely unpleasant and can include nausea, weakness, sweating, faintness, and on occasion, diarrhea after eating.
  • In some cases, the effectiveness of the procedure may be reduced if the stomach pouch is stretched and/or if it is initially left larger than 15 to 30 cc.
  • Rerouting of bile, pancreatic, and other digestive juices beyond the stomach can cause intestinal irritation and ulcers.
  • The lower stomach pouch and segments of the small intestine cannot be easily visualized using x-ray or endoscopy if problems such as ulcers, bleeding or malignancy should occur.
  • Talk with your surgeon about the possible surgical risks.