Gastric Sleeve vs. the Gastric Bypass

Gastric Sleeve vs. the Gastric Bypass

Gastric Sleeve v Gastric Bypass: What’s the Difference?

The most frequent question that I get these days is “which weight-loss operation is the best for me?” While there have been many bariatric procedures that have evolved over time, the Roux-en-y gastric bypass and the gastric sleeve seem to have withstood the test of time. Other weight-loss surgeries have been tried and have either fallen short in expectations over time, or some remain experimental and long-term outcomes are not yet known.

Gastric Sleeve

The sleeve gastrectomy has been around for a long time. It was first introduced as a part of the duodenal switch operation. However, in the past 15 years it has been found to be a good stand-alone operation, resulting in good weight loss. The operation consists of making a tube out of the stomach from the end of the esophagus to the lower portion of the stomach. The tube is narrow, perhaps a little bigger around than your index finger. This tube restricts how much food you can eat. We make it small because it will stretch out over time to be 35-40% the size of a normal stomach, which is what you need to maintain your weight loss.

With the gastric sleeve weight loss is rapid at first with most weight loss occurring in the first 6 months. As the sleeve stretches, weight loss slows and is complete at about 1 year. At that point you can expect to lose about 70% of your excess weight. There is also good resolution or improvement in obesity-related illnesses associated with the gastric sleeve. Type II diabetes goes into remission about 60-70% of the time, with medications no longer needed. Hypertension and sleep apnea resolve or improve about 60-65% of the time. In short, the sleeve gastrectomy only restricts how much you eat. The food that is eaten is absorbed properly, so vitamin and mineral deficiencies are uncommon.

Gastric Bypass

The Roux-en-y gastric bypass has also been around for a long time–since the 1960’s. For many bariatric surgeons,  the bypass is considered to be the gold standard for weight-loss surgery. The bypass has two parts to the operation. The first  part consists of creating a pouch out of the upper part of the stomach which is connected to the esophagus. It too is small–about the size of an adult thumb and can contain about 1-1.5 ounces. It will also stretch to contain about 6-8 ounces over 1 year, allowing you to maintain your weight loss. The second part of the operation is the bypass. The first part of the small intestine is bypassed by connecting the second portion of the small intestine to the pouch.


The weight loss achieved with the bypass is about the same as the sleeve gastrectomy. Similarly, there is also a favorable impact on obesity-related illnesses. The resolution or improvement seen in hypertension and sleep apnea is about the same for the bypass as it is for the sleeve. However, the change in the anatomy associated with the bypass results in a much better remission rate for type II diabetes. We see resolution in diabetes in about 85% of gastric bypass patients in our practice. The downside of the gastric bypass is that over time it is possible to develop vitamin and mineral deficiencies because of the malabsorptive component. To prevent this from occurring,  vitamin and mineral supplements are recommended, and with regular follow-up these deficiencies are uncommon.

So, now to answer the question…”which weight-loss operation is the best for me?” If you have Type II diabetes, the gastric bypass is the best operation for remission and a possible cure. However, if you don’t have type II diabetes, then the sleeve will result in about the same weight loss with a much lower risk of nutritional deficiencies.

As always, if we can answer any questions, please don’t hesitate to give us a call at 303-861-4505. If you are interested in attending one of our free weight-loss informational seminars, please check our website for details. They are being held the third Thursday of each month at Parker Adventist Hospital. Hope to see you there!

All the best,
Tom Brown, MD

Vertical Sleeve Gastrectomy

Roux gastric bypass

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