Gastric Bypass

Gastric bypass is considered to be the gold-standard for the surgical treatment of morbid obesity. This has been proven by many studies published in the recent literature. In most institutions with an invested interest in obesity surgery, gastric bypass is the operation performed in the majority of such patients since 1990. During this procedure no part of the stomach or the intestine is removed. What actually happens during this operation, is the division of the stomach and the intestine, each at a specific site, and then a reconnection of the divided parts in a different fashion. This creates a rerouting of the ingested food and the normal digestive juices in such a way that four different mechanisms are put to action, all with the result of weight loss.

1. Because of the very small upper compartment of the stomach, patients cannot eat many solids.

2. Because no actual digestion takes place in essentially half of the digestive tract, a portion of the ingested food does not get absorbed.

3. Ghrellin, the appetite hormone, is significantly decreased, so the patients do not crave for food.

4. In case that a patient consumes a bigger quantity of high-calorie fluid (“sweets”), this rapidly comes in contact to the intestine; not the stomach. This is not well tolerated and produces an unpleasant feeling, which discourages patients from such foods.

It is important to emphasize that this operation does not lead to diarrhea, as is the case with the so called “biliopancreatic bypass”, which is an operation that may be indicated for patients with extreme obesity. Because of the decreased appetite, produced by the decreased level of ghrellin, patients with gastric bypass do not feel the urge to eat a lot. The role of this can be realized when someone compares a patient after a gastric bypass with one with a band. The latter does want to eat, does have a lot of appetite, but is not able to because of the forceful restriction to solids that the band exerts. This uninterrupted “drive to eat” is precisely why patients with a band eventually try to “cheat” the operation and they manage to do this by consuming high-calorie fluids and so they regain weight. Gastric bypass can be performed laparoscopically and is probably the best surgical treatment for patients with morbid obesity and BMI higher than 45.