Duodenal Switch Complications

Do you suffer from obesity? Have you tried diet and exercise plans recommended by your insurance company or doctor but haven’t achieved the success you want? You’re not alone. According to research from the Harvard T.H. Chan School of Public Health, in 2019 around 40% of Americans suffered from obesity, and 18% were considered morbidly obese.

If you’ve looked into methods of treating obesity, you’re probably familiar with weight loss surgery. There are many types of weight loss surgery, but in this article, we’ll talk about the loop duodenal switch, also known as the SADI-S or SIPS procedure. We’ll talk about the requirements to get this procedure, the benefits of getting this type of bariatric surgery, as well as possible loop duodenal switch complications and risks and how you can prevent them during recovery.

What Is A Duodenal Switch Procedure?

The loop duodenal switch is a surgical procedure, also known as the SIPS or SADI-S, and may be the most effective obesity treatment available. It is a newer version of the now outdated biliopancreatic diversion with duodenal switch (BPD-DS) that allows for more weight loss while reducing risk. It is a malabsorptive and restrictive surgery. These terms mean that the small intestine absorbs fewer calories and nutrients and that the stomach is reduced in size. This combination of malabsorption and restriction makes this surgery very effective. About 85% of the stomach is removed and the remaining part is formed into a tube-like or sleeve-like pouch. 

The first portion of the small intestine just after the stomach, known as the duodenum, is then divided. The portion of the duodenum immediately after the stomach is then connected to a downstream loop of your small intestine. The food that you consume will now bypass about half of your small intestine, resulting in your body absorbing fewer calories and nutrients each time you eat. SADI-S surgery also affects hormones in your stomach and intestine to reduce hunger, make you feel fuller, and control your blood sugar. As such, it is seen as a very effective obesity treatment for weight loss as well as for diabetes.

The purpose of this bariatric surgery is to help you lose excess weight; resolve obesity related health problems such as Type 2 diabetes, high blood pressure, high cholesterol, and sleep apnea; and also decrease your chances of developing potentially serious weight-related health issues such as:

  • Infertility
  • Heart disease
  • Stroke
  • Cancer
  • Early death

A loop duodenal switch is generally a surgical procedure that is a last resort after all other methods and weight loss programs, such as strict diet and exercise, have been exhausted. Duodenal switch surgery isn’t for everyone suffering from obesity and the screening process to determine whether you qualify is extensive. Loop duodenal switch patients must make a big commitment—you must be prepared to make permanent changes including a life-long dedication to a strict vitamin and mineral regime.

Since studies show that it’s much more cost-effective to treat obesity with bariatric surgeries than with other methods, your loop duodenal switch surgery may be covered by your insurance plan. To confirm this you can contact your insurance provider or Colorado state Medicare office to find out if your weight loss treatment will be covered. 

Are You A Candidate For A Duodenal Switch Procedure?

There are numerous other types of bariatric surgeries, such as gastric sleeve surgery and gastric bypass, in addition to the loop duodenal switch procedure. The basic criteria needed to qualify for weight loss surgery with most insurances includes suffering from morbid obesity and having health-related issues that go along with obesity. Here is what’s required to get a duodenal switch procedure:

  • BMI (Body Mass Index) equal to or higher than 40.

Or a BMI of 35-39 with a serious obesity-related comorbidity such as one of the following conditions:

  • High blood pressure
  • High cholesterol
  • Type 2 diabetes
  • Sleep apnea
  • Pseudotumor cerebri
  • Cardiovascular condition

What Are The Risks and Complications Of The Duodenal Switch Procedure? 

Although the loop duodenal switch has helped thousands of people get their health and their life back, there are also some potential duodenal switch risks and complications that can be associated with this kind of weight loss surgery. Some risks come from bariatric surgery in general and others are tied to the procedure itself. 

Immediately after this weight loss surgery, there will be a normal amount of swelling and pain around the incision site. Some less common duodenal switch risks are infection and obstructions. Long term complications can vary from patient to patient.

Here are some nationally reported duodenal switch risks and complications:

Abdominal Complications

A patient’s intestines may take time to adapt, making bowel movements looser and more frequent directly after the procedure. This side effect will most likely lessen over time, but in some cases can be permanent. Most commonly a person that normally has one well-formed bowel movement every day can expect two looser stools per day after surgery. This is why patients who suffer from irritable bowel syndrome (IBS) are not good candidates for a duodenal switch. Additional, abdominal complaints can include bloating, frequent flatulence as well as gas and stool that may be abnormally foul-smelling.

Low Vitamin Levels

This is one of the more common duodenal switch risks. Because this is a procedure that decreases absorption, a person will develop vitamin deficiencies unless adequate and very consistent supplementation is used. Patients who don’t follow their dietary and vitamin regimen closely may find themselves suffering from potentially serious health conditions as a result. Checking vitamin levels at least yearly for the first 5 years after surgery as well as close monitoring of protein levels will need to be completed by the bariatric specialist.

For example, in rare cases, patients have reported night blindness from being vitamin A deficient when not adequately supplementing. This is why fat-soluble vitamins, such as A, D, E, and K are crucial to avoid malnutrition. 


Patients may be more susceptible to developing gallstones due to the rapid weight loss following surgery. This can lead to some patients needing gallbladder removal.

Intestinal Irritation

Although the risks are low, the rerouting of bile, pancreatic and other enzymes around the stomach can cause irritation, bacterial overgrowth, and other complications in the intestines. Patients who use GI irritants such as nicotine, alcohol, drugs, or caffeine after surgery can experience ulcers.

Acid Reflux

Worsened acid or bile reflux is another possible duodenal switch complication. This is why patients with moderate to severe heartburn or GERD may not be good candidates for this operation. If a patient experiences an increase in heartburn following surgery, their doctor can prescribe antacids and other medicines to treat this.


A staple line leak is a very rare but serious complication of any weight loss surgery. Although parallel rows of staples completely seal the tissue and a leak test will be performed before the completion of surgery, patients may still be at risk for developing a leak if their staple line were to break down either as a result of dietary non-compliance or from impaired blood flow to the healing staple line. Fortunately, leaks are very rare. 

Other complications of duodenal switch surgery can include:

  • Pneumonia
  • Blood clots, including pulmonary embolism (a blood clot going to the lung)
  • Heart attack
  • Bleeding
  • Hernias at the incision site
  • Psychological issues
  • Death (very rare and reported in up to 1 in 1,000 bariatric surgery cases of all types nationally)

It’s important to note that while the above weight loss complications are not unheard of, they are very rare. Overall, when working with a careful bariatric surgeon at a center of excellence, the risk of experiencing either a major complication or death is similar to that of the most minor abdominal operations such as a gallbladder removal. At the Bariatric and Metabolic Center of Colorado, our double-board-certified bariatric surgeon has an extremely low complication rate and will work with you closely to mitigate any potential operative risks through careful preoperative planning and meticulous operative technique.

Ways To Mitigate Duodenal Switch Complications

While not every potential complication can be prevented, careful planning and compliance can minimize these risks and prevent many potential complications. Here are some of the ways to prevent duodenal switch risks.

Vitamin Deficiency—To decrease the risk of this serious complication, you’ll need to strictly follow your doctor and healthcare team’s suggested diet and vitamin supplementation after the surgery. Consistency is the key here.

Gallstones, Leaks, Intestinal Irritation, and Ulcers—Most bariatric surgeons will conduct an intra-operative leak test to make sure that patients do not have a leak before leaving the operating room. Leak prevention can then be optimized by following a careful bariatric post-operative course. Routine checkups and careful compliance are critical to prevent, detect, and treat ailments such as gallstones, irritation, and ulcers.

Psychological Issues—As your body changes, your relationships may as well. Some people might not be as happy for you as you want them to be and others may actually be jealous. As you become more active, your activities and hobbies often change. This can place a strain on some relationships. Your doctor can suggest support groups with others like you to help you get through these transitions and enrich your experience. 

What Are The Benefits Of A Duodenal Switch Procedure?

The SADI-S is a very safe procedure, and can commonly help patients to lose 100 pounds or even more and keep that excess weight off. While it is still surgery, it’s much safer for the carefully compliant patient than historical procedures or outdated bariatric surgeries such as Lap Band surgery. Here are some of the benefits that you can expect—from recovery to results—after your surgery:

Lose More Weight Faster

The loop duodenal switch surgery has advantages over other types of weight loss surgeries, like gastric sleeve surgery and Lap Band. By both restricting the amount of food you eat and the amount of calories your body absorbs, loop duodenal surgery is a one-two punch that translates to serious weight loss. With this type of surgery, you’ll lose weight faster and more effectively than with gastric bypass, gastric sleeve surgery, or Lap Band surgery. Your chances of gaining the weight back are also very low. 

Expected weight loss is a huge benefit to this obesity treatment. One study found that around 94% of the duodenal patients who participated lost more than 70% of their excess weight one year after the surgery. The same study stated that 62% of patients lost 75% of their excess weight after three years and over 30% lost 81% of their excess weight at five years. Other studies have indicated that weight loss following a SADI-S procedure can be about 15% better than weight loss following the gastric bypass (formerly the gold standard for weight loss). Patients will harvest their maximum benefit when they are also very engaged in building the behavioral changes needed to complement the surgery; indeed, some success stories result in even more weight loss than the above numbers.

Minimally Invasive

At the BMCC this procedure is performed using minimally invasive surgical techniques. These techniques use technology like robotics or laparoscopic tools that show the surgeon an image of your abdomen. It requires only a small incision for the minimally invasive equipment, meaning faster healing, less pain and scarring, and faster recovery. This approach is also used in gastric sleeve surgery, gastric bypass surgery, and other types of bariatric surgeries.

Another advantage of minimally invasive surgery is a shortened stay in the hospital afterward so you can get on the road to recovery and living your best life more quickly. 

The More Active, The Fewer Duodenal Switch Complications

Your loop duodenal switch procedure can help resolve your type 2 diabetes, minimize your risk of heart attack by resolving your metabolic disease, mitigate your obstructive sleep apnea and lower your cholesterol levels. 

But weight loss surgery isn’t a cure all. After recovery, good eating habits and regular exercise are requirements begin to feel better about yourself, your health, and life in general. With significantly less weight to carry and much better health, you’ll also feel free to enjoy exploring the beautiful wilderness of Colorado and a fuller life.

The Bariatric and Metabolic Center of Colorado Is Here For You

At the BMCC, bariatric surgeon Dr. Joshua Long works hard to minimize the duodenal switch risks. He repairs any hernias you have in bariatric surgery, prescribes antacids as needed, discusses options for support groups, and much more. The BMCC is a certified ASMBS comprehensive MBSAQIP bariatric center, meaning that complications are rare. Dr. Long has earned awards for his skill in the operating room and takes an empathetic approach to each patient he serves.

If you would like to know more about duodenal switch risks, the overall procedure, or weight loss surgery in general, schedule an appointment with our friendly team. 

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This page was medically reviewed by Dr. Joshua Long, MD, MBA, FACS, FASMBS. Dr. Long is a double-board-certified bariatric surgeon and bariatric medical director for Parker Adventist Hospital.
Full Bio: Dr. Joshua Long, MD, MBA, FACS, FASMBS
Page Updated: January 6th, 2023

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