Bariatric Surgery FAQ

Duodenal Switch

Duodenal Switch - Bariatric Fusion

There are a number of bariatric surgery options available. It can be difficult understanding the differences and which procedure may be the right option for you.

Whatever the reason may be for considering bariatric surgery, this article will help you understand whether a duodenal switch procedure is right for you.

We will also provide you the facts as to how and why it has such a high success rate.

What This Article Covers:

What is a Duodenal Switch?

A duodenal switch procedure can be described as an extension of a gastric sleeve operation. They are both weight loss surgeries that begin with a sleeve gastrectomy and involve changing the stomach into a smaller, tube-shaped pouch.

In the case of a duodenal switch surgery, after the tube-shaped stomach is created, the small intestine is cut and divided, leaving only a few feet of intestine for food to pass through.

In basic terms, the first portion of the small intestine is divided and attached to the last portion of the small intestine.

This procedure is less common than other bariatric operations. It results in restriction, malabsorption of vitamins/minerals, and changes of hormones in the gastrointestinal tract.

How a Duodenal Switch Works

Duodenal switch surgery results in weight loss by altering the absorption of

food. This occurs when bypassing a large portion of the intestine responsible for the digestion and absorption of certain nutrients. This is known as “malabsorptive” weight loss methods.

During this procedure 70-80 percent of the stomach is also removed, thereby limiting the amount of food you will be able to consume. This is otherwise known as “restrictive” weight loss methods.

Duodenal switch procedures have been seen to have the most maintainable weight loss results when compared to other forms of weight loss surgeries. This can largely be accredited to the combination of malabsorptive and restrictive methods for weight loss.

Weight Loss

Most people who have had a duodenal switch surgery can expect to lose between 60 and 80 percent of their excess body weight within a year after surgery.

Duodenal switch surgeries have been shown to initiate the most rapid weight loss after the initial surgery when compared to other bariatric procedures.

Rapid weight loss that is seen initially following surgery will start to slow down after 6 months. The weight loss timeline will look different for everyone, depending on your weight before surgery and existing comorbidities.

Below is a timeline of projected excess weight loss after a duodenal switch

duodenal switch surgery


  • 60-65% at one year
  • 70-75% at 18 months
  • 75% at 2 years

The likelihood of sustained weight loss at 3 years after duodenal switch surgery is about 85%.

Weight Gain After Duodenal Switch

Although duodenal switch surgery has been proven to be one of the most effective surgery options for weight loss, it is still possible for patients to regain weight years after the procedure.

Aging and changes in metabolic functions contribute to postoperative weight gain, but are not the sole factor in post-bariatric surgery weight gain.

Anatomical changes may also occur over time. The stomach will naturally stretch in order to accommodate a larger volume of food. Therefore, it is your responsibility to maintain your diet plan, as well as stay active.

Remaining mindful of dietary choices and activity levels will help to minimize the amount of weight gained in the long term.

To avoid weight gain after bariatric surgery it is important to have regular consultations with your healthcare provider and registered dietitian.

Long Term Effects of Duodenal Switch Surgery

After duodenal switch surgery, several physiological changes will occur in the body due to the alteration of the gastrointestinal tract. Therefore, the first 30 days after the operation will be extremely different from the first 6 months to a year post-op.

A few important aspects of recovery are listed below:

  • Stay hydrated: You should aim to drink at least 64 oz of fluid per day. It may be a challenge at first, but it is an essential part of recovery and healing.
  • Prioritize protein intake: You will require between 80 to 120 grams of protein throughout the day. You may be recommended a different amount of protein by your dietitian based on metabolic needs. It can be challenging reaching daily protein goals through meal times alone, therefore using a bariatric protein supplement is recommended.
  • Vitamin and mineral supplementation: Duodenal switch procedures are restrictive and malabsorptive, meaning the risk for nutrient deficiencies are increased. With the extensive portion of the small intestine being bypassed, it is common to see a higher risk in fat-soluble vitamin deficiencies when compared to other bariatric procedures. In order to avoid vitamin and mineral deficiencies, take a bariatric multivitamin supplement that includes additional fat-soluble vitamins A, D, E, K to meet your bariatric needs.
  • Digestive issues: As with any surgery, a duodenal switch procedure will have potential risks and complications. Digestive complications, such as GERD (gastroesophageal reflux disease), heartburn, and IBS-like symptoms will have to be monitored and managed in the long term.

Duodenal Switch vs Gastric Sleeve

Both surgeries aim to reduce weight by limiting the amount of food you can consume in a sitting, and thereby maintaining a caloric deficit.

The following are a few ways in which the two procedures differ:

  • Gastric sleeve operations can be done through small key-hole incisions, whereas duodenal switch procedures require those same incisions plus additional ones in order to gain access to the small intestine.
  • Gastric sleeve surgery is less invasive requiring a shorter hospital stay when compared to a duodenal switch procedure.
  • Gastric sleeve procedures initiate weight loss by restricting the volume of food a patient can consume, whereas duodenal switch procedures initiate weight loss through restriction and malabsorption.
  • The stomach muscle, called the pylorus, is preserved after a duodenal switch procedure. This is not the case for gastric sleeve procedures. Therefore, dumping syndrome is less of a risk after duodenal switch surgery when compared to sleeve gastrectomy.
  • In order to be eligible for a sleeve gastrectomy, your BMI must be above 40 or above 35 paired with additional comorbidities. In order to be eligible for duodenal switch surgery, your BMI is likely above 50.


Duodenal switch and gastric sleeve procedures result in weight loss and both have numerous benefits. Overall, duodenal switch surgery is an effective and safe way to manage obesity.

However, duodenal switch surgery is more complex and invasive than other bariatric operations and can come with risks and possible complications.

You should have a thorough discussion with your healthcare provider on what option may be the best for your individual needs. You will go through an extensive screening process before you even undergo surgery to ensure it is the right decision for your needs.

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**This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your physician or another qualified health provider with any questions in regards to a medical condition. A qualified healthcare professional can best assist you in deciding whether a dietary supplement is suitable based on your individual needs.

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