Bariatric Surgery: Understanding the Complications, Risks, and Side Effects

complications, risks, and side effects from bariatric surgery

Bariatric surgery, also known as weight loss surgery, refers to a variety of procedures performed on people who are obese or severely overweight. The goal of bariatric surgery is to help people lose weight and improve obesity-related conditions like type 2 diabetes, high blood pressure, and sleep apnea. While bariatric surgery can be an effective weight loss tool when traditional diets and exercise have failed, it does carry risks of complications both during and after surgery. Being informed on the potential complications and side effects is important when considering bariatric surgery as a weight loss option.


Types of Bariatric Surgery Procedures

There are several different types of bariatric surgery procedures, including:

  • Gastric bypass - This procedure divides the stomach into a small upper pouch and a larger lower pouch that is bypassed. The smaller stomach pouch restricts food intake, and bypassing part of the stomach reduces calories absorbed.

    gastric bypass surgery
  • Sleeve gastrectomy - In this procedure, approximately 75% of the stomach is surgically removed, creating a narrow tube-shaped stomach. This reduces stomach size and appetite.

    gastric sleeve surgery
  • Adjustable gastric band - An inflatable band is placed around the upper portion of the stomach, creating a small pouch that limits food intake. The band can be adjusted to restrict food intake more or less over time.

    gastric band surgery
  • Biliopancreatic diversion with duodenal switch - This more complex procedure removes most of the stomach while bypassing a large portion of the small intestine. This significantly reduces calorie absorption from food.


Risks and Complications of Bariatric Surgery

While bariatric surgery can be effective for significant weight loss, all types of bariatric surgery procedures carry risks of complications, both in the short term after surgery as well as over the long term. Around 20% of bariatric patients develop some sort of short-term or long-term complication. Potential risks and complications include:


Short term risks

  • Infections and bleeding
  • Leaks from staple lines or sutures
  • Blood clots, including deep vein thrombosis and pulmonary embolism
  • Breathing problems like pneumonia or collapsed lung
  • Heart problems such as irregular heartbeat, heart attack, or stroke

Longer term risks and complications

  • Bowel obstruction or hernia
  • Gallstones
  • Nutritional deficiencies, if difficulty absorbing nutrients
  • Low blood sugar
  • Ulcers at the surgical site
  • Vomiting, if eating more than pouch can hold
  • Band slipping partly out of place (gastric banding)
  • Need for revision surgery if complications occur or weight loss goals not reached

The risk of complications is generally higher with more complex procedures like gastric bypass versus gastric banding. However, any bariatric surgery does require a hospital stay and carries risks. Certain factors like high BMI, age, smoking, diabetes, and sleep apnea can increase an individual's risks with bariatric procedures.


Side Effects of Bariatric Surgery

In addition to serious surgical risks and complications, bariatric surgery can result in both short and long term side effects:


Short term side effects

  • Pain or discomfort at the surgical site(s)
  • Fatigue and weakness as recover from procedure
  • Dumping syndrome - nausea, cramps, diarrhea after eating
  • Constipation from reduced food intake
  • Acid reflux or heartburn

Longer term side effects

  • Changes in bowel habits - constipation or diarrhea
  • Malnutrition and related conditions like anemia
  • Excess skin left after significant weight loss
  • Psychological issues like depression, relationship changes, food addiction

Considering the Complications

Bariatric surgery has become safer over time as surgeons have gained more experience with obese patients. There are different surgical options to choose from, and each has its own benefits and potential risks. When deciding which weight loss surgery is right for a patient, the surgeon considers these technical and metabolic factors. As surgeons have done more of these procedures, complications and mortality rates have gone down. This means the benefits of bariatric surgery now clearly outweigh the risks for most obese patients, especially those with obesity-related health conditions. In general, bariatric surgery is considered safe for broader use in obese individuals struggling with their weight and health.



Author: Carrie H.


Carrie is a passionate health and nutrition writer who transforms complex medical research into accessible, evidence-based content to empower readers to make informed choices about their wellbeing. With a background in science and a dedication to helping others live healthier lives, she provides thoughtful analysis of the latest studies and practical, actionable advice readers can apply to their own lives.


Reviewed By: Dr. Huffman


Dr. Huffman is an accomplished board-certified bariatric physician with extensive clinical experience and expertise in treating obesity. He has trained countless healthcare providers and founded American Bariatric Consultants to develop highly sought-after protocols, training materials and continuing education used widely by medical societies, hospitals and physicians. Dr. Huffman's impact reaches far beyond direct patient care, as he actively prepares the next generation of physicians to achieve board certification in bariatrics, thereby exponentially expanding access to this vital medical treatment.