The gastric bypass, also known by its longer name, the Roux-en-Y gastric bypass, is a procedure that was initially developed over 50 years ago. It was designed as a procedure for patients with acid reflux, but they realized that the patients were also losing a lot of weight and keeping it off. It remains an excellent procedure for treating reflux, and it remains the procedure with the longest track record in bariatric surgery. It involves dividing the upper stomach into a small “gastric pouch” which is then sewn to a portion of the small intestine that is referred to as the Roux limb. This allows the food that is eaten to “bypass” the rest of the stomach and the first portion of the small intestine. The gastric pouch is normally only about an ounce in size (30 milliliters), and patients feel full after much smaller portions. In addition, they no longer absorb all the calories that they eat, because of the part of the intestine that is now bypassed. Patients can expect to lose 60-70% of their excess body weight after gastric bypass, and that weight loss is expected to persist.
The gastric bypass also has an effect known as dumping. This is a side effect that occurs when sugary foods or liquids are eaten, and this sugar quickly pours into the small intestine. This often results in nausea, abdominal cramping, and diarrhea. This is an effect that does not happen if patients eat the meals that they learn about during their nutritional counseling before bariatric surgery. Some patients choose the gastric bypass knowing that the dumping will help them avoid these types of sugary foods and liquids, and other patients decide that the gastric bypass is not for them because of this.
It is essential that patients take multivitamins as instructed after the gastric bypass, and we like to see our patients come back at least once a year for the rest of their lives to make sure they are doing well and not developing vitamin deficiencies.