Gastric bypass surgery is considered to be relatively low risk. Complications, however, can occur, and complication rates vary between individual surgeons. Read below about our complication statistics, and how our results compare to what’s reported in the published gastric bypass literature.

Gastric Bypass Complications

Gastric bypass surgery complications can be categorized as early (occurring within 30 days of surgery), or late (occurring after 30 days).

Early gastric bypass surgery complications include leaks, blood clots, bleeding, infection, dehydration, stricture, etc. Late complications include vitamin/mineral deficiencies, internal hernias, ulcers, alcohol abuse, hypoglycemia, weight regain, etc.

Below is a discussion about leak (the most important early complication), and 30-day complication rate (measure of all early complications).

Gastric Bypass Leak

A leak is a serious and feared complication that can occur after gastric bypass surgery. A leak is a hole that occurs in the stomach or intestine early after surgery before complete healing has occurred. A gastric bypass leak can result in a serious infection, the need for subsequent procedures/operations, and a prolonged hospital stay.

Gastric Bypass Leak – Our Results

Dr. Oliak’s leak rate for laparoscopic gastric bypass (first time gastric bypass, and LAP-BAND® revision to gastric bypass) is <0.1% (1 in 1,095 operations).*

Dr. Oliak’s <0.1% gastric bypass leak rate is significantly lower than the average gastric bypass surgeon leak rate (see table and discussion below), which is approximately 1.6%.*

Quality of surgery and patient care matters! Our program prioritizes high-quality surgery, comprehensive and thorough patient education, frequent follow-up, and ongoing support to achieve great patient outcomes.*

Our program

Gastric Bypass Leak – Published Studies

There have been many studies published on gastric bypass leak rates, by many surgeons, over the past 20+ years. The most recent large studies on gastric bypass leak report the overall average gastric bypass leak rate to be 1-2% (see table below).*

This, however, is not the leak rate for all surgeons. Some surgeons achieve lower leak rates than the average, and some achieve higher leak rates than the average. Published studies report individual surgeon report leak rates to be as low as 0%, and as high as 8%.*

Differences in individual surgeon leak rates are largely due to differences in surgeon skill and surgical technique.

Gastric Bypass Leak – Published Studies*

Author Date Published Study Type Total Patients Overall Leak Rate*
Zellmer et al 2014 review – 28 studies 10,900 1.9%
Chang et al 2018 review – 71 studies 107,874 1.14%
Kumar et al 2018 2015 COE Data 41,080 1.6%

* Leaks can occur after gastric bypass surgery. Past performance is not necessary indicative of future results.

Gastric Bypass 30-day Complication Rate

30-day complication rate is a common outcomes measure for many different types of surgeries. The statistic is relatively easy to get from hospital billing data so large numbers of patients can be evaluated, and the statistic is useful medically because most surgery related complications occur within the first month after surgery.

One recent large study, described below, evaluated 30-day gastric bypass (and gastric sleeve) complication rates.

Kumar et al, in a 2018 study, evaluated 41,080 gastric bypass patients that had surgery in 2015, and reported the overall 30-day gastric bypass complication rate to be 11.7%.* Kumar did not report on the variation in complication rates between different surgeons/programs.

Our 30-day complication rate for gastric bypass operations performed 2010-2017 is 5.7%, half the rate as in the review study above.*

Another recent large study, described below, evaluated complication rate variation between different bariatric surgery programs.

Ibrahim et al, in a 2017 study, evaluated the 30-day complication rate for serious complications at 165 accredited bariatric surgery center of excellence programs nationwide. This study, of note, looked at serious complications that occurred after all weight loss operation (gastric bypass, gastric sleeve, LAP-BAND®), not just gastric bypass.

The authors found that the rate of serious complications occurring within 30 days of surgery varied 17-fold (yes, 17-fold!), from 0.6% to 10.3%, across the 165 different bariatric surgery center of excellence programs nationwide.

Our 30-day serious complication rate, using the same criteria and dates as in this study, is 0.6%.*

Quality of surgery and patient care matters! Our program prioritizes high-quality surgery, comprehensive and thorough patient education, frequent follow-up, and ongoing support to achieve great patient outcomes.*

Our program

* Outcomes vary after weight loss surgery. Gastric bypass complications can happen. Past performance is not necessary indicative of future results.

Late Gastric Bypass Complications

There is the potential for gastric bypass complications to develop long-term after gastric bypass surgery. Regular long-term follow-up is important after gastric bypass surgery to screen for potential complications. When complications develop, early diagnosis and treatment is important. Possible long-term complications include vitamin/mineral deficiencies (common), bowel obstructions (2-3%), ulcers (5%), weight regain (10-30%), and alcohol abuse.

  • 0.1% leak rate*
  • 76% excess weight loss 1 year after bypass*
  • 66% excess weight loss 10-13 years after bypass*

Gastric Bypass before & after

See more
  • Tami
  • Procedure:Gastric Bypass
  • Weight Lost: 75 lbs
  • Excess Weight Lost: 85%
  • Disclaimer: Individual results vary
I had gastric bypass 8 years ago with Dr. Oliak and I would do it again tomorrow. It was the…
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