Site Map

Gastric bypass surgery

Bariatric surgery - gastric bypass; Roux-en-Y gastric bypass; Gastric bypass - Roux-en-Y; Weight-loss surgery - gastric bypass; Obesity surgery - gastric bypass; Metabolic and bariatric surgery or MBS

Gastric bypass is surgery that helps you lose weight by changing how your stomach and small intestine handle the food you eat.

After the surgery, your stomach will be smaller. You will feel full with less food.

The food you eat will no longer go into some parts of your stomach and small intestine that absorb food. Because of this, your body will not get all of the calories from the food you eat.

Images

Roux-en-Y stomach surgery for weight loss
Adjustable gastric banding
Vertical banded gastroplasty
Biliopancreatic diversion (BPD)
Biliopancreatic diversion with duodenal switch
Dumping syndrome

Description

You will have general anesthesia before this surgery. You will be asleep and pain-free.

There are 2 steps during gastric bypass surgery:

Gastric bypass can be done in two ways. With open surgery, your surgeon makes a large surgical cut to open your belly. The bypass is done by working on your stomach, small intestine, and other organs.

Another way to do this surgery is to use a tiny camera, called a laparoscope. This camera is placed in your belly. The surgery is called laparoscopy. The scope allows the surgeon to see inside your belly.

In laparoscopic surgery:

Advantages of laparoscopy over open surgery include:

This surgery takes about 2 to 4 hours.

Why the Procedure Is Performed

Weight-loss surgery (also called metabolic and bariatric surgery or MBS) may be an option if you have moderate to high-risk obesity and have not been able to lose enough weight through diet and exercise.

Health care providers often use the body mass index (BMI) and health conditions such as type 2 diabetes (diabetes that started in adulthood) and high blood pressure to determine which people are most likely to benefit from MBS.

Gastric bypass surgery is not a quick fix for obesity. It will greatly change your lifestyle. After this surgery, you must eat healthy foods, control portion sizes of what you eat, and exercise. If you do not follow these measures, you may have complications from the surgery and poor weight loss.

Be sure to discuss the benefits and risks with your surgeon.

This procedure may be recommended if you have:

Risks

Gastric bypass is major surgery and it has many risks. Some of these risks are very serious. You should discuss these risks with your surgeon.

Risks of having anesthesia and surgery in general include:

Risks of gastric bypass include:

Before the Procedure

Your surgeon will ask you to have tests and visits with other health care providers before you have this surgery. Some of these are:

If you smoke, you should stop several weeks before surgery and not start smoking again after surgery. Smoking slows recovery and increases the risks for problems. Tell your provider if you need help quitting.

Tell your surgeon or nurse:

During the week before your surgery:

On the day of surgery:

After the Procedure

Most people stay in the hospital for 1 to 4 days after surgery.

In the hospital:

You will be able to go home when:

Be sure to follow instructions for how to care for yourself at home.

Outlook (Prognosis)

Most people lose about 10 to 20 (lbs) or (4.5 to 9 kgs) a month in the first year after surgery. Weight loss will decrease over time. By sticking to your diet and exercise program from the beginning, you will lose more weight.

You may lose one half or more of your extra weight in the first 2 years. You will lose weight quickly after surgery if you are still on a liquid or pureed diet.

Losing enough weight after surgery can improve many medical conditions, including:

Weighing less should also make it much easier for you to move around and do your everyday activities.

To lose weight and avoid complications from the procedure, you will need to follow the exercise and eating guidelines that your provider and dietitian have given you.

Related Information

Body mass index
Obstructive sleep apnea - adults
Type 2 diabetes
Coronary heart disease
Obesity
Laparoscopic gastric banding
Bathroom safety for adults
Surgical wound care - open
Preventing falls
When you have nausea and vomiting
Gastric bypass surgery - discharge
Your diet after gastric bypass surgery
Laparoscopic gastric banding - discharge
After weight-loss surgery - what to ask your doctor
Before weight-loss surgery - what to ask your doctor

References

Eisenberg D, Shikora SA, Aarts E, et al. 2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO): Indications for metabolic and bariatric surgery. Surg Obes Relat Dis. 2022;18(12):1345-1356. PMID: 36280539 pubmed.ncbi.nlm.nih.gov/36280539/.

Richards WO, Khaitan L, Torquati A. Morbid obesity. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 21st ed. St Louis, MO: Elsevier; 2022:chap 48.

Schirmer B. Operations for morbid obesity. In: Yeo CJ, ed. Shackelford's Surgery of the Alimentary Tract. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 63.

Sullivan S, Edmundowicz SA, Morton JM. Surgical and endoscopic treatment of obesity. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 8.

BACK TO TOP

Review Date: 8/22/2022  

Reviewed By: Debra G. Wechter, MD, FACS, General Surgery Practice Specializing in Breast Cancer, Virginia Mason Medical Center, Seattle, WA. Internal review and update on 07/16/2023 by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ADAM Quality Logo
Health Content Provider
06/01/2025

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics. This site complied with the HONcode standard for trustworthy health information from 1995 to 2022, after which HON (Health On the Net, a not-for-profit organization that promoted transparent and reliable health information online) was discontinued.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2024 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.