Roux-en-Y gastric bypass combines restriction and malabsorption.
To understand a gastric bypass procedure, it is helpful to have a working knowledge of normal gastrointestinal (GI) functions. As food enters the mouth, it mixes with digestive enzymes and passes into the stomach. The stomach has a normal capacity of almost a quart and a maximum capacity of almost two quarts. As food is digested in the stomach, it passes into the first part of the small intestine, or the duodenum. This part of the GI tract is mostly important to the absorption of sugar. The second portion of the small intestine is the jejunum, which is largely responsible for the absorption of protein, fat and vitamins. The ileum is the third section of the small intestine and absorbs the largest portion of consumed fat, including fat soluble vitamins like E, A, D and K. From the ileum, any non-digested ingredients enter the large intestine and are eventually eliminated as waste.
In Roux-en-Y gastric bypass, the stomach is divided to create a small stomach “pouch” that limits the amount of food that can be eaten. The pouch is a little larger than a golf ball and can only hold about two ounces of food.
The small intestine is then cut part way down the second segment (jejunum), and the lower part is attached to the small, newly formed stomach pouch. This causes food to bypass the first section of the small intestine (duodenum) and upper part of the second section, reducing calorie absorption.
The larger, excluded stomach, known as the gastric remnant, is closed and surgically separated from the new, smaller stomach pouch. This remnant of the stomach no longer receives food but has a normal blood supply, keeping it healthy though it is no longer in use.
This information is intended only as an overview of a Roux-en-Y gastric bypass procedure. Should you and your surgeon decide that this surgery is appropriate for you, you will receive more extensive education regarding the potential risks, side effects and complications as well as pre- and post-surgery guidelines to follow for your health.