Bariatric Surgery

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Definition & Facts

Bariatric surgery is an option if you have severe obesity and have not been able to lose enough weight to improve your health using other methods or have serious obesity-related health problems. The surgery makes the stomach smaller and sometimes changes the small intestine.
Woman measuring weight while doctor writing notes in clinic

Types of Bariatric Surgery

In the United States, surgeons use three types of bariatric operations most often: gastric band, gastric bypass, and gastric sleeve. Surgeons use a fourth operation, duodenal switch, less often. Each type of surgery has advantages and disadvantages.

Bariatric Surgery Benefits

Bariatric surgery can improve many health problems related to obesity, such as type 2 diabetes, high blood pressure, unhealthy cholesterol levels, and sleep apnea. Surgery also may lead to improved physical function and mood, and better quality of life.

Bariatric Surgery Side Effects

Bariatric surgery may cause side effects right after surgery or later. Side effects may include infection, diarrhea, nutritional shortages, gallstones, and hernias.

​​Potential Candidates of Bariatric Surgery

Bariatric surgery may be an option for adults and teens who have severe obesity and obesity-related health problems such as type 2 diabetes, sleep apnea, high blood pressure, or heart disease.

​Clinical Trials

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support basic and clinical research into many disorders.

Related Conditions & Diseases

Your Digestive System & How It Works

The digestive system is made up of the gastrointestinal (GI) tract-also called the digestive tract-and the liver, pancreas, and the gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus.

Related Research

See more about obesity research at NIDDK.

This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.

The NIDDK would like to thank:
Anita Courcoulas, M.D., M.P.H, University of Pittsburgh School of Medicine; Walter J. Pories, M.D., F.A.C.S., Brody School of Medicine, East Carolina University