Gastric Sleeve vs. Gastric Bypass

Gastric sleeve and gastric bypass surgeries are both very common bariatric procedures designed to help those with morbid obesity achieve significant weight loss. While they are similar in many ways, the two techniques have distinct differences. Choosing between the two often comes down to understanding exactly how each one alters the digestive system, since that difference affects everything from weight loss timelines to long-term nutritional needs.

How Are Gastric Sleeve and Gastric Bypass Similar?

Gastric sleeve and gastric bypass both involve decreasing the size of the stomach to ultimately lead to weight loss. By having a smaller stomach, this restricts the amount of food patients need to eat before feeling full. However, the method of creating this smaller stomach size differs between the two procedures. Both are also generally considered safe, well-established procedures with decades of outcomes data behind them, and both require a committed, long-term approach to diet and lifestyle to achieve lasting results.

How Does Gastric Sleeve Surgery Work?

During gastric sleeve surgery (also known as a vertical sleeve gastrectomy), our Chicago bariatric surgeons remove 70 to 80 percent of the stomach and resection it to create a thin “sleeve” in which food can be stored. Because this procedure only removes stomach tissue without rerouting the intestines, it’s considered a purely restrictive surgery. Digestion still follows its normal path, food just passes through a much smaller stomach, which also produces less of the hunger hormone ghrelin and can help reduce appetite.

How Does Gastric Bypass Surgery Work?

In gastric bypass surgery (also known as a Roux-en-Y gastric bypass), the stomach is reduced into a small pouch by first dividing the stomach and then attaching a Y-shaped segment of the small intestine to the pouch. This causes food to bypass part of the small intestine to reduce the amount of calories and nutrients that are absorbed. Because it combines a smaller stomach with reduced nutrient absorption, gastric bypass is often described as both a restrictive and malabsorptive procedure, and patients may need closer monitoring of vitamin and mineral levels afterward.

Key Differences Between the Two Procedures

Gastric sleeve surgery requires a single step, while gastric bypass surgery involves two steps. Both procedures are often performed laparoscopically. Because gastric bypass involves the additional step of rerouting the intestine, it’s generally the more complex of the two surgeries, though both are performed routinely and safely by experienced bariatric surgeons.

Patients considering either option should also know that gastric bypass has historically shown a slight edge in early weight loss and in improving conditions like acid reflux, while gastric sleeve tends to carry a somewhat lower risk of long-term nutritional deficiencies since it doesn’t alter how the intestines absorb nutrients.

Lifestyle Changes After Surgery

Lifestyle changes are necessary after both bariatric surgeries to ensure a successful outcome. This includes making dietary changes like consuming less food, since the new stomach size can only accommodate a small amount, as well as taking vitamins to ensure you are meeting your nutritional needs. Regular follow-up visits with your surgical team also help catch and address any nutritional gaps early, which is especially important for gastric bypass patients given the added malabsorption involved.

Learn Which Is Right for You

For more information about gastric sleeve surgery, gastric bypass surgery, or another weight loss procedure, please contact our experienced team at Suburban Surgical Care Specialists / Kane Center to schedule your consultation. Our surgeons will evaluate your candidacy and help you find the most beneficial procedure for improving your long-term health.

Editor’s Note: The original version of this post was published November 6, 2020.