Mini Gastric Bypass vs Duodenal Switch

Overview of Mini Gastric Bypass Surgery and Duodenal Switch Surgery Comparison

Choosing between mini gastric bypass vs duodenal switch is a particularly difficult decision to make due to the high excess weight loss and reduction of obesity-related comorbidities. In order to make an informed decision, we separate the mini gastric bypass vs duodenal switch to educate consumers on the best choice for you. It is important to know all the advantages, benefits, disadvantages, and what to expect from each type of weight loss procedure.

Mexico Bariatric Center collected the pros and cons, expected results, and long-term weight loss you can expect for both mini gastric bypass surgery and duodenal switch surgery.

Procedures Explained: Pros and Cons

Mini Gastric Bypass Surgery - Mini Gastric Bypass vs Duodenal Switch

Mini Gastric Bypass Surgery

Mini Gastric Bypass surgery is an effective weight loss procedure which forms a new, small stomach pouch that is shaped like a tube. The new stomach bypasses about 20% (2 to 7 feet) of the small intestine, primarily the duodenum section. The mini gastric bypass resumes digestion with the jejunum.

Duodenal Switch Surgery - Mini Gastric Bypass vs Duodenal Switch

Duodenal Switch Surgery

The Duodenal Switch surgery removes about 70% of the stomach, leaving behind a new, sleeve-shaped stomach. New stomach is “switched: to the last 40% of the small intestines. The duodenal switch resumes connection within the common channel of the small intestines.

Notable Differences

The notable difference between these two operations is that mini gastric bypass surgery on has alters the anatomy through one connection to the intestine, while duodenal switch surgery uses two connections. These connection points are called “anastomosis.” Apart from that, the mini gastric bypass provides slightly less expected excess weight loss (%EWL) than the duodenal switch.

Which Procedure is Best For You?

  • Highest Amount of Excess Weight Loss (%EWL) – Duodenal Switch Surgery (DS)
  • Less Invasive Surgery – Mini Gastric Bypass Surgery (MGB)
  • Low Complication Rate – Mini Gastric Bypass Surgery
  • Less Number of Potential Side Effect – Mini Gastric Bypass Surgery
  • Lowest Cost of Procedure –  Mini Gastric Bypass Surgery in Tijuana, Mexico
  • Highest Reduction in Comorbidities and Health-Related Problems – Duodenal Switch Surgery (DS)
  • Most Popular Surgery: Mini Gastric Bypass Surgery (MGB) as of now

Find Out if You Qualify For Mini Gastric Bypass or Duodenal Switch Surgery HERE

Mini Gastric Bypass vs Duodenal Switch Surgery - Pros and Cons Infographic

Comparing Mini Gastric Bypass vs Duodenal Switch

Type of Surgery

Mini Gastric Bypass

Mini Gastric Bypass Surgery

Duodenal Switch

Duodenal Switch Surgery

Method of Weight Loss

Restrictive & Malabsorptive

  • New Stomach Formed
  • Alters Digestion

Restrictive & Malabsorptive

  • Stomach Size Reduced
  • Alters Digestion

Stomach Alterations

New stomach created: Stoma

  • The stomach is turned into a tube-shaped, with a new smaller stomach (stoma) created with intestines.

Stomach size reduced

  • 70-85% of the stomach is removed – similar to gastric sleeve surgery.

Changes to Intestine

Cut and Bypassed

  • The stomach uses a single connection to the small intestine, known as single anastomosis.

Intestines “Switched”

  • New stomach is “switched,” to the last 6 feet of the small intestines around to alter the digestion process and limit food absorption.
  • Uses double anastomosis, or connections to the small intestines.

Operating Time

  • 1.5 to 2.5 hours
  • 4 hours

Average Hospital Stay

  • 2 to 3 nights
  • 3 nights

Time off Work

  • 2 to 3 weeks
  • 3 to 4 weeks

Recovery Time

  • 3 weeks
  • 3 weeks


  • High excess weight loss
  • Low-risk procedure in comparison to duodenal switch
  • 70-80% Expected Weight Loss
  • Most weights lost in the first year


  • Major and complicated surgery with associated risks.
  • Leakage, bleeding, vomiting can occur.
  • Daily supplements and vitamins needed.
  • Dumping syndrome is common.
  • None reversible.
  • Most complications of any surgery.
  • More frequent bowel movements.
  • Vitamins and supplements needed.

Surgery Description

Small pouch (about 1/20-30cc) Pouch is connected to the small intestine where food and digestive juices are separated for the first 3 to 5 feet. The RNY significantly restricts the volume of food that can be eaten.

Long vertical pouch (about 4-5 oz or 120-150cc). The duodenum (first portion of the small intestine) is attached to the last 6 feet of small intestine, where food and digestive juices are rejoined after 12 feet. Moderate restriction of the volume of food that can eat. Provides moderate malabsorption of fat, which can cause bloating and diarrhea.

Realistic Expectations

  • Provides mild malabsorption of nutrients
  • Patients can expect to lose an average of 76% of excess weight
  • Less than patients with Duodenal Switch
  • Patients can expect to lose 75% to 80% of excess weight.
  • Some patients can lose too much weight
  • More risk of nutritional deviancies than with the RNY gastric bypass

Post Surgery Dietary Info

  • Bypass patients need to be on vitamins for the rest of their life to aid in digestion
  • Patients must eat three meals/day.
  • Patients must strictly adhere to protein and vitamin supplements to avoid deficiencies. (Multivitamins, ADEK vitamins, Calcium, and Iron for Menstruating women)


The new stomach will hold between 4-6 ounces of food instead of the average 40 ounces.

The mini bypass is less complicated than the RNY because of only one connection to the intestines.

The Duodenal efficacy is effective for patients with a BMI of > 50kg/m2. Those with a BMI of <45kg/m2 may lose too much weight.

The Duodenal Switch has a higher incidence of complications than any other weight loss surgery.

2-Year Follow-Up

  • Patients maintained a 65% loss of excess body weight.
  • A rather new procedure with less long-term weight loss data
  • Patients maintained a 79% loss of excess body weight.
  • 9% (at 1 year) and 6% (at 2 years) of patients had failed to lose at least 50% of their excess weight.