Bariatric Surgery Side Effects

What are the side effects of bariatric surgery?

Side effects may include

  • bleeding
  • infection
  • leaking from the site where the sections of the stomach or small intestine, or both, are stapled or sewn together
  • diarrhea
  • blood clots in the legs that can move to the lungs and heart

Rarely, surgery-related problems can lead to death.

Other side effects may occur later. Your body may not absorb nutrients well, especially if you don’t take your prescribed vitamins and minerals. Not getting enough nutrients can cause health problems, such as anemia and osteoporosis. Gallstones can occur after rapid weight loss. Some doctors prescribe medicine for about 6 months after surgery to help prevent gallstones. Gastric bands can erode into the stomach wall and need to be removed.

Vitamins and nutrients in pill format sitting in a person’s hand.
Taking your prescribed vitamins and minerals will help you get enough nutrients.

Other problems that could occur later include strictures and hernias. Strictures—narrowing of the new stomach or connection between the stomach and small intestine—make it hard to eat solid food and can cause nausea, vomiting, and trouble swallowing. Doctors treat strictures with special instruments to expand the narrowing. Two kinds of hernias may occur after bariatric surgery—at the incision site or in the abdomen. Doctors repair hernias with surgery.

Some research suggests that bariatric surgery, especially gastric bypass, may change the way your body absorbs and breaks down alcohol, and may lead to more alcohol-related problems after surgery.

July 2016

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