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Types of Surgeries

Roux-en-Y Gastric Bypass Surgery

Roux-en-Y Gastric Bypass (RYGB) Bariatric Surgery Overview

Dr. Michel Gagner has been an instrumental agent in the evolution of the Gastric Bypass (GB) procedure into what it has become today. His team performed the second GB while he was working at the Cleveland Clinic in 1995, and was the first to perform a hand-assisted GB in 1996. He brought forth multiple modifications that were adopted worldwide and have become standard: the use of an antecolic and antegastric limb in 1996, the use of a split omentum in 1996, and the use of trans-oral techniques. Dr. Gagner is also an experienced revisionist of the GB, being the first surgeon to convert both a gastric band and a VBG into a GB by laparoscopy in 1996. Today, the laparoscopic RYGB is an increasingly popular choice for weight loss surgeries in Montreal

Roux-en-Y gastric bypass surgery combines gastric reduction and intestinal malabsorption to help patients lose excess weight. The procedure involves creating a small gastric pouch near the esophageal sphincter. The first part of the intestine is cut in two: the lower section (Roux limb) is attached to the newly-formed gastric pouch, and the upper section (Bilio-Pancreatic limb) is attached further down the Roux limb. Digestive juices from the excluded stomach pouch and Bilio-Pancreatic limb flow into the Roux limb of the small intestine, thus constraining digestion and ingestion further down the intestinal pathway, which helps patients lose weight.

On average, the surgery takes one hour to complete; patients are discharged 1-2 days post-op, and return to work after 2-4 weeks. According to the Cleveland Clinic, initial weight loss following surgery is substantial, typically around 70% of excess weight within the first year or two. While some regain occurs over time, the enduring average long-term loss stands at 50% of excess weight, a figure maintained over two decades.

Candidate Characteristics
Ideal candidates for Roux-en-Y Gastric Bypass weight loss surgery have certain key characteristics that enhance the likelihood of successful outcomes. Generally, individuals with a Body Mass Index (BMI) of 40 or higher, or those with a BMI of 35 to 39.9 along with obesity-related health issues, are prime candidates for a laparoscopic gastric bypass. 

It should be noted, however, that individual candidacy must be assessed by at our weight loss clinic in Montreal to confirm whether or not the RYGB is the best option to help a patient achieve rapid weight loss.  

Advantages and Disadvantages


  • Good weight loss
  • Good remission rate of diabetes
  • More long-term data than other metabolic and bariatric surgery options


  • Dumping syndrome (sweating, dizziness)
  • Hypoglycemia
  • Bowel obstructions
  • Lifelong need for vitamins and minerals
  • Increased rate of gastric ulcers


Risks of Surgery

  • Ulcers, 5-15% in collective series
  • Bowel obstruction, 3-5% in collective series
  • Leakage, less than 1% in collective series
  • Bleeding, less than 1% in collective series

Did you know we have a support group?

Your questions and concerns have most likely been asked and answered in our support group. Moderated by our dietitians, nurses, and staff. We provide you with reliable patient education and resources to help you throughout this life-changing process.