Medically Reviewed by:Peter F. Rovito, MD, FACSBariatric Surgeon
Complications of gastric bypass surgery:
- Are almost never life-threatening (gastric bypass has a 99.8% survival rate)
- Occur in up to 10% patients (9 out of 10 patients do not experience complications)
- Include 20 possible issues
- Can often be avoided with the right behavior and choices
Read the sections below for everything you need to know about gastric bypass complications.
TABLE OF CONTENTS
Click on any of the topics below to jump directly to that section
- General Safety
- Complication Rates
- List of Complications
- How to Minimize Risk
- Patient Community & Expert Advice
- The surgery is very safe. It has a 99.8% survival rate
Compare the 0.22% mortality rate (99.8% survival rate) of gastric bypass surgery to other well-known procedures:
- Gallbladder removal: 0.15% mortality rate (1)
- Hip replacement: 0.29% mortality rate (2)
- Cesarean section (“C-Section”): 0.40% mortality rate (3)
In other words, gastric bypass is about as risky as gallbladder surgery and a lot less risky than a hip replacement or a C-section.
Typical gastric bypass results include:
- 1-year weight loss: 65% of excess weight, on average
- 5-year weight loss: 60% of excess weight, on average, after weight regain
- Complete resolution or significant improvement for at least 15 obesity-related health conditions, including diabetes, hypertension, and sleep apnea
See our Gastric Bypass Results section for more information about weight loss and health benefits to expect.
- Up to 10% of patients have at least one complication (see details below)
Tap here to expand a table of complication rate studies.
|Study||# of gastric bypass patients in study||Complication Rate||Year|
|Study A||1,573||At least one complication – 9.5%||2016|
|Study B||111||Early complications – 10% Late complications – 15.3%||2007|
|Study C||70||Early complications – 10% Late complications – 8.1%||2006|
The following list of gastric bypass complications may appear intimidating, but keep in mind that 9 out of 10 patients don’t experience any complications and that there are several things you can do to minimize your risk.
Further down the page we’ll direct you to resources that will help you find, interview and choose the right bariatric doctors and help you understand how to minimize your risks.
First, let’s review the list of potential complications (click the links below for more information including definitions and treatments, then click the ‘Back’ button in your browser to come back to this page)…
- Alcohol Use Disorder (AUD)
- Bleeding (also called “Hemorrhage”)
- Blood clots or blood clot symptoms (also called “thrombus”)
- Bowel function changes (sometimes diarrhea, but more often constipation after gastric bypass surgery)
- Bowel obstruction (also called an “internal hernia”)
- Candy Cane Syndrome
- Dumping syndrome
- Dyspepsia (indigestion)
- Gastroesophageal reflux disease (GERD)
- Hypoglycemia (low blood sugar)
- Incision(al) hernia
- Intolerance to certain foods – With a changed stomach size or digestive system, there will be certain foods that you’ll need to avoid and certain diet habits you’ll need to maintain. See our Bariatric Diet section for details.
- Kidney stones
- Leaks ( including gastrointestinal leaks and staple line leaks )
- Nausea and vomiting
- Nutritional deficiency, especially iron and calcium. See our Bariatric Vitamins page for more information about getting the vitamins your body needs after gastric bypass surgery.
- Organ injury during surgery
- Marginal Ulcer
- Wound infection
For a complete list and comparison of complications relating to all types of bariatric surgery, see our Bariatric Surgery Complications page.
- Make sure gastric bypass is the most appropriate weight loss procedure for you
- Choose the right surgeon for you
We have several pages that will help you determine the best way to reduce your risk during and after gastric bypass surgery. Follow one of the below links depending on where you are in the process:
- Your first step is to make sure that you select the surgery that is most appropriate for your situation. Different surgeries carry different risks for different people. Our Types of Bariatric Surgery page compares and contrasts the safest and most effective procedures.
- If you haven’t done so already, next review our Bariatric Surgery Complications page. In addition to providing a full list of definitions and treatments, it also illustrates which complications apply to each type of surgery, factors that increase your risks and 10 ways to minimize your risk of complications.
- As mentioned above, your surgeon can have a lot to do with your outcome. For example, one study evaluated a surgeon over his first 300 laparoscopic gastric bypass patients (4). Following were his results as he gained experience:
Tap here to expand a table of surgeon performance over time.
Obviously, being in the 3rd group is the most desirable.
A separate and much larger study of over 15,000 patients in Michigan had similar findings about surgeon experience (5):
Tap here to expand a table of the study’s results.
|# of procedures performed by surgeon over 3 years||Rate of serious complications occuring within 30 days of surgery|
|Less than 100 cases||3.8%|
|100 – 249 cases||2.4%|
|Greater than or equal to 250 cases||1.9%|
Most surgeons offer free seminars that teach you about your weight loss surgery options and their offices experience, total procedures performed and specific results. The seminars also allow you to get to know the surgeon prior to a one-on-one consultation (usually free as well).
You can also review our Bariatric Doctors page to learn how to interview multiple doctors and choose the best one.
- Your behavior before and after surgery also directly and significantly impacts the complications of gastric bypass surgery. See the following pages to learn what you’ll need to do to be successful over the short and long-term:
- Gastric Bypass Recovery
- Life After Weight Loss Surgery
- Bariatric Diet (what you eat) & Bariatric Eating (how you eat)
- Exercise after gastric bypass surgery
- You can read about the experiences of other gastric sleeve patients
- You Can "Ask the Expert"
Ask the Expert & Patient Experiences*
We would love to hear your experiences with gastric bypass complications. Your insights are invaluable to making sure other people have the tools to meet their goals.
We would also be happy to answer any questions you may have about gastric bypass complications.
Please use the form below to share your experience or ask a question.
Questions From Other Visitors*
Click below to see contributions from other visitors to this page.
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