Gastric Bypass

# Procedures that alter digestion are known as malabsorptive procedures. Malabsorptive techniques reduce the length of intestine that comes in contact with food so that the body absorbs fewer calories. According to the American Society for Bariatric Surgery and the National Institutes of Health, Roux-en-Y gastric bypass is the current gold standard procedure for weight loss surgery. In this procedure, stapling creates a small (15 to 20cc) stomach pouch. The remainder of the stomach is completely stapled shut and divided from the stomach pouch. It is not completely removed. The outlet from this newly formed pouch empties directly into the lower portion of the jejunum, called the Roux limb, thus eliminating the duodenum and a small portion of the jejunum from the absorptive circuit. The omitted segment is connected into the side of the Roux limb of the intestine creating the "Y" shape that gives the technique its name. The length of either segment of the intestine can be adjusted to produce lower or higher levels of malabsorption.


  • The duodenum being bypassed, poor absorption of iron and calcium can result in the lowering of total body iron and a predisposition to iron deficiency anemia.
  • A chronic anemia due to Vitamin B12 deficiency may occur. The problem can usually be managed with Vitamin B12 pills or injections.
  • 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. Some patients are unable to eat any form of sweets after surgery.
  • Metabolic bone disease in some patients, resulting in bone pain, loss of height, humped back and fractures of the ribs and hip bones.

All the above listed deficiencies can be easily managed through a proper diet and vitamin and calcium supplements. It is mandatory for patients undergoing gastric bypass to consume a multivitamin and calcium supplement daily.