Understanding Restrictive and Malabsorptive Procedures
Your surgeon will make recommendations about which bariatric surgery is most appropriate for your individual weight loss needs, but it is helpful to understand how each procedure impacts the gastrointestinal system before moving forward.
Procedures for bariatric surgery fall into two categories based on how they alter the way your body intakes and digests food: restrictive and malabsorptive. Depending on the weight loss surgery, these methods may be employed separately or in conjunction with one another.
Restrictive surgical procedures reduce the patient’s intake of food by decreasing the stomach’s overall size. These procedures typically involve less complex surgical techniques.
During a sleeve gastrectomy, your surgeon removes part of the stomach and separates the remaining section to create a smaller pouch that can hold significantly less than a full-sized stomach. Gastric banding procedures involve placing an adjustable band around the stomach to separate it into two parts, creating a small, upper pouch that controls how much food you can eat.
Malabsorptive procedures work by bypassing lengths of the small intestine, thereby reducing the calories, fat and nutrients absorbed by the body during digestion. Such procedures tend to be more complex and require a deeper understanding of the way your body digests food.
After food is ingested, it mixes with acids and other juices in your stomach that help the body break down fats, carbohydrates and complex proteins into more easily absorbed units. Once food has been properly broken down, it passes through the pylorus and into the small intestine.
The small intestine is divided into three different parts. Food first passes into the duodenum, where iron, calcium and vitamins A, D, E and K are absorbed while bile from the liver and juices from the pancreas aid in digestion. Next, it passes into the jejunum and ileum, in which other nutrients, calories and fats are absorbed, and then through the large intestine, where the remaining fluids are absorbed.
In gastric bypass patients, restrictive procedures are used to separate a small pouch from the rest of the stomach, while a malabsorptive procedure connects this pouch directly to the lower section of the jejunum. By bypassing the duodenum and part of the jejunum, the digestive system absorbs fewer calories, fat and nutrients. The effects of malabsorption can be increased and decreased by changing the lengths of different intestinal segments.