Gastric Bypass (Roux-en-Y)

The Roux-en-Y Gastric Bypass – often just called gastric bypass – is considered the ‘gold standard’ of weight loss surgery and is the most commonly performed bariatric procedure worldwide. The BMI recommendations for the Gastric Bypass are that you have a BMI at least 35, or a BMI of at least 30 with one or more weight-related medical complications

During the procedure the stomach is simply divided in two - a small upper stomach about the size of a small lemon (to restrict food intake), leaving the main larger part of the stomach completely untouched.

A Y-shaped section of the small intestine is attached to the small upper stomach to allow food to bypass the main stomach, the duodenum, and the upper small intestine which is the part of the bowel where many fats and sugars are normally absorbed, This reduces the absorption of nutrients and thereby reduces the calorie intake, resulting in weight loss.


  • Performed using minimal-access techniques such as mini-lap surgery or laparoscopic surgery
  • Most patients stay in the hospital for only three days (in on Wed/ out on Sat, or in on Thu/out on Sun)
  • Many weight related medical problems can be cured or significantly approved
  • Excess weight loss of 70-80% *
  • Diabetes resolution rate of 50%-70%*
  • Improvement in quality of life
  • Reversible procedure
  • No part of the stomach is moved or removed.

*disclaimer: results vary from person to person


  • Surgical complications commensurate with moderate abdominal surgery
  • Need to take multivitamins, iron and calcium.


The reference for 4th bullet point in advantages is:
Adams TD, Davidson LE, Litwin SE, et al. Health benefits of gastric bypass surgery after 6 years. JAMA 2012; 308:1122-1131

Reference for 5th bullet point in advantages is:
Buchwald H et al. Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis. Am J Med  2009; 122: 248 - 256.

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