Roux-en-Y Gastric Bypass—Open Surgery
(Bariatric Surgery; Weight-Reduction Surgery)
Pronounced: Roo-n-y gas-trick bye-pass
by Karen Kassel, MS, RD, MEd
Roux-en-Y gastric bypass is a surgery for obesity. It changes the stomach and small intestine to cause weight loss by:
Reasons for Procedure
The surgery treats severe obesity. A calculation called body mass index ( BMI) is used to determine how overweight or obese you are. A normal BMI is 18.5-25.
Roux-en-Y gastric bypass is a weight loss option for people with:
The success of gastric bypass surgery depends on your commitment to lifelong health habits. If lifestyle changes are made and maintained, the benefits of bariatric surgery include:
Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:
Before your procedure, talk to your doctor about ways to manage factors that may increase your risk of complications such as:
What to Expect
Prior to Procedure
Each bariatric surgery program has specific requirements. Your program will likely include the following:
Leading up to your procedure:
General anesthesia will be used. You will be asleep.
Description of Procedure
To prepare you for surgery, an IV will be placed in your arm. You will receive fluids and medications through this line during the procedure. A breathing tube will be placed through your mouth and into your throat. This will help you breathe during surgery. You will also have a catheter placed in your bladder to drain urine.
An 8-10 inch incision will be made to open the abdomen. Surgical staples will be used to create a small pouch at the top of your stomach. This pouch, which can hold about 1 cup of food, will be your new, smaller stomach. A normal stomach can hold 4-6 cups of food.
Next, the small intestine will be cut and attached to the new pouch. With the intestinal bypass, food will now move from the new stomach pouch to the middle section of the small intestine. It will skip the lower stomach and the upper section of the small intestine.
Finally, the upper section of the small intestine will be attached to the middle section of the small intestine. This will allow fluid that the lower stomach makes to move down the upper section of the small intestine and into the middle section.
When the bypass is completed, the incisions will be closed with staples or stitches.
You will be taken to the recovery area for monitoring. You will also be given pain medication.
How Long Will It Take?
About 2 hours
How Much Will It Hurt?
Anesthesia will prevent pain during surgery. Pain and discomfort after the procedure can be managed with medications.
Average Hospital Stay
The usual length of stay is 2-5 days. Your doctor may choose to keep you longer if complications arise.
At the Hospital
While you are recovering at the hospital, you may receive the following care:
During your stay, the hospital staff will take steps to reduce your chance of infection such as:
There are also steps you can take to reduce your chance of infection such as:
You will need to practice lifelong healthy eating and exercising habits. Keep in mind after your surgery:
Your new stomach is the size of a small egg. It is slow to empty, causing you to feel full quickly. Therefore, you need to eat very small amounts and eat very slowly:
Call Your Doctor
Contact your doctor if your recovery is not progressing as expected or you develop complications such as:
If you think you have an emergency, call for emergency medical services right away.
American Society for Metabolic and Bariatric Surgery
National Institute of Diabetes and Digestive and Kidney Diseases
Weight Loss Surgery
Bariatric surgery. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T483434/Bariatric-surgery . Updated October 23, 2017. Accessed December 22, 2017.
Bariatric surgery. Merck Manual Professional Version website. Available at:
...(Click grey area to select URL)
Updated December 2016. Accessed December 22, 2017.
Bariatric surgery. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/weight-management/bariatric-surgery. Accessed December 22, 2017.
Maciejewski ML, Livingston EH, Smith VA, et al. Survival among high-risk patients after bariatric surgery. JAMA. 2011;305(23):2419-2426.
Obesity surgery: Roux-en-Y gastric bypass. Cleveland Clinic website. Available at: https://my.clevelandclinic.org/health/treatments/17285-obesity-surgery/roux-en-y-gastric-bypass. Accessed December 22, 2017.
Roux-en-Y gastric bypass. Columbia University Medical Center website. Available at:
...(Click grey area to select URL)
Accessed December 22, 2017.
Roux-en-Y gastric bypass weight-loss surgery. Johns Hopkins Medicine website. Available at: https://www.hopkinsmedicine.org/healthlibrary/test_procedures/gastroenterology/roux-en-y_gastric_bypass_weight-loss_surgery_135,65. Accessed December 22, 2017.
9/2/2009 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T483434/Bariatric-surgery : The Longitudinal Assessment of Bariatric Surgery (LABS) Consortium. Perioperative safety in the longitudinal assessment of bariatric surgery. N Engl J Med. 2009;361(5):445-454.
6/24/2011 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T483434/Bariatric-surgery : Pontiroli AE, Morabito A. Long-term prevention of mortality in morbid obesity through bariatric surgery. a systematic review and meta-analysis of trials performed with gastric banding and gastric bypass. Ann Surg. 2011;253(3):484-487.
Last reviewed November 2018 by EBSCO Medical Review Board Marcin Chwistek, MD
Last Updated: 12/20/2014
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at firstname.lastname@example.org. Our Health Library Support team will respond to your email request within 2 business days.