17 things you should know about the duodenal switch

17 Things You Should Know About the Duodenal Switch (DS)

January 30, 2017

Making the decision to undergo weight loss surgery is a life-changing proposition. It is imperative when devising an informed and educated decision, in collaboration with your surgeon, regarding the short and long-term outcomes of weight loss surgical procedures. The Duodenal Switch (DS) (Bilio-pancreatic diversion with Duodenal Switch) has the best long-term excess weight loss maintenance of all weight loss surgical procedures. However, the Duodenal Switch has lifetime care needs that must be taken into consideration.

Description of Duodenal Switch (DS)

Duodenal Switch is a procedure that offers restriction from the pyloric preserving Vertical Sleeve Gastrectomy and malabsorption from the Duodenal Switch.

1) Unrestrictive Diet

After DS, unlike other procedures with significant dietary and lifestyle restriction, patients with the duodenal switch are able to enjoy a relatively unrestrictive diet.

2) Hess Method Versus Standard

The absorptive capacity of our small bowel is individual and depends on the length of the bowel, the thickness of the layers of the small bowel and a number of other variables. It is important that the lengths of the common and the alimentary limbs are made in proportion of the total length of the small bowel in a patient. For example, lets look at the following: If two patients both have a BMI of 50, and both are told by the surgeon that they are getting 100 cm of common channel and 300 cm of alimentary limb because of “standard” lengths of doing the DS, imagine what will happen to them if one of them has 1000 cm total length and the other patient has only 500 cm total length of bowel. This will result in one of the patients having twice absorption after the surgery and possibly less weight loss long term. In contrast, if both patients have the DS by making their common channel 10% of the total length and the alimentary channel at 40-50% then both patients will end up with the same percentage of absorption after surgery.

3) Preservation of the Pyloric Valve

Preservation of the Pyloric Valve avoids the complication of marginal ulcers and dumping syndrome. The post-pyloric duodenum helps with iron and calcium absorption and this is why the iron deficiency is not as significant as it is after the gastric bypass. The degree of weight loss and maintenance after DS has been documented to well beyond 15 years.

4) Resolution of Metabolic Co-Morbidities and Related Co-Morbidities

There is no question that Duodenal Switch has the highest resolution of co-morbidities. This may be due to the synergistic effects of restriction, malabsorption, hormone and chemical components.

5) Hydration

The smaller sleeved stomach and less surface area of the small intestines make it important to focus on daily hydration needs. A minimum of 64+ ounces daily, depending on individual needs, is recommended.

6) Protein

Protein is required for many bodily functions and is a daily lifetime requirement after DS. Adequate protein intake is important to healthy tissue, healing process and normal physiologic processes.

7) Vitamins and Minerals

There are basic needed daily vitamins and minerals for your entire life following Duodenal Switch. Special attention to the Fat-Soluble Vitamins A, D, E, and K following Duodenal Switch is important due to fat malabsorption. Vitamin and mineral needs should be based on laboratory studies and individual vitamins. I recommend dry water miscible forms of Vitamin A, D, E, and K and these should be adjusted based the patients’ laboratory studies. Calcium and Vitamin D supplements need to be managed by also following a PTH level. Calcium level, nor Vitamin D on their own do not give an adequate picture.

8) Blood Work

Yearly laboratory studies, at the minimum, are needed for the lifetime of a patient. These lab studies should include fat-soluble vitamin levels.

9) Follow-Up

Stay in contact with your surgeon. Your surgeon may be able to assist you in determining your needs for your weight loss surgery with the ability to modify and impact treatment and care guidelines by attendance of national, international meetings and keeping apprised of new research to facilitate the best outcomes for patients.

10) Procedures and Tests After Duodenal Switch

CT scans after Duodenal Switch should have BOTH IV and Oral contrast to visualize the bilio-pancreatic limb. Some radiologists will replace water for oral contrast. This will not be acceptable or useful if a bowel obstruction is being ruled out. An upper GI series will not diagnose a bilio-pancreatic limb obstruction. After Duodenal Switch you cannot have an Endoscopic retrograde cholangio-pancreatography ERCP, however, Magnetic resonance cholangio-pancreatography MRCP or surgically assisted ERCP are possible.

11) Support Groups

The best patient outcomes happen with consistent and supportive aftercare. I find the best outcomes happen when patients keep in touch with a Duodenal Switch group, surgeon, etc. on the changes in DS research and needs. This can be in the form of webinars, in person or other online forums. It is important, however, not to replace your surgeon with non-medical advice for health issues.

12) Not Everything is Duodenal Switch or WLS Related

Often weight loss surgery, in general, is blamed for many health related issues. However, this may not be the case. Finding providers willing to investigate, understand and treat the patient is a crucial part of post-op care and lifetime care.

13) Operative Report and Lab Results

Part of patient education is to know your surgical anatomy well enough to explain it to others. I would also venture to say, that at least one family member or significant other should also know your DS needs and anatomy. I feel this is important for any major health care related process.

14) Bathroom Changes

The bathroom changes after Duodenal Switch are often managed by diet. There is a slight increase in bowel movements daily in the literature, from 1-2 to 2-3 bowel movements daily. Following dietary guidelines, vitamin and minerals supplementation, and learning your body’s triggers will avoid this side effect. However, misinformation is given when patients are discouraged from looking into the DS by being told that they will be needing diapers, or cannot leave the house because of incontinence. IF a patient is experiencing uncontrolled bowel issues, it needs to be evaluated and an underlying cause identified.

15) Pitfalls of Duodenal Switch

Overeating carbohydrates can cause weight gain. In the same way that some RNY patients experience the complication of "dumping", some DS patients will have a stronger odor of gas and stools with high carbohydrate consumption. The same can occur with artificial sweeteners.

16) Risks of Duodenal Switch

The Duodenal Switch operation incorporates many steps involving different parts of the GI track. This is different than most other weight loss surgical procedures. Furthermore, unlike all other procedures (Gastric Bypass, Sleeve Gastrectomy, Adjustable Gastric Banding where all patients, regardless of their excess weight or co-morbidities get the same operation), Duodenal Switch can be customized to provide the best long-term outcome for the patient from the aspects of excess weight loss percentage and also resolution of the co-morbidities, such as diabetes, hyperlipidemia, and other. This customization is optimized when a surgeon tailors the lengths of the common and the alimentary limbs to each patient's individual condition and not cookie cut the bowel lengths.

17) Lifestyle Changes - Not a Panacea

As with any weight loss surgery, Duodenal Switch assists in one area of your life. As uncommon as they may be, it will not fix eating issues, behaviors, or other compounding stressors of life. Career, relationship issues, family dynamics, mental health and coping issues, will not be resolved by any weight loss surgery. This is a time for re-learning, introspection, and possibly further assistance in other aspects physically, emotionally and mentally. All weight loss surgeries have limitations to their effectiveness.


Duodenal Switch is an incredible long-term intervention with long-lasting results, but as with all things worthwhile, it requires daily attention. It is in the patient's best interest to choose a weight loss surgical procedure that gives the best results the first time, to optimize weight loss, metabolic effect and to avoid revisions in the future. The tendency has been to gravitate toward simple procedures, without giving much value to the poor outcome of those less invasive procedures. Finding a surgeon with the skill, technique and the ability to assist and guide you through the process and follow-up is a key component to Duodenal Switch.

17 things you should know about the duodenal switch


Dr. Ara Keshishian is Director and Surgeon at Central Valley Bariatrics. He has performed more than 2,000 Duodenal Switch procedures and 500+ revisions from other procedures such as RNY, Lap-Band & VSG to the DS since 1999. He has published several research articles on weight loss surgery topics.
Read more articles from Dr. Keshishian!