Gastric bypass surgery accelerates weight loss by creating deliberate caloric malabsorption. Also called Roux-en-Y (pronounced “roo-en-why”) gastric bypass, this bariatric surgery creates a small stomach pouch and bypasses a portion of the small intestines, so you feel fuller faster and absorb fewer calories.Â
No part of the stomach is actually removed during a gastric bypass procedure. Rather, the stomach is divided to form an egg-sized pouch for food; the larger defunct part of the stomach remains, but it no longer receives or digests food.
The procedure also decreases your levels of ghrelin, the hunger hormone. Bariatric surgeons say a combination of these factors results in weight loss.
Dr. Nicole Basa, a bariatric surgeon in Austin, answers this RealSelf member's top questions about weight loss surgery options, including whether it's Worth It.
In a mini gastric bypass, or loop gastric bypass, a surgeon attaches a loop of small intestine to the gastric pouch, rather than dividing the small bowel and attaching the Roux-en-Y to the gastric pouch.
Doctors on RealSelf strongly caution against the procedure, and the vast majority of bariatric surgeons will not perform it, due to its high likelihood of complications down the road.Â
Mini gastric bypass may appear to be a cost-saving, less invasive alternative, but it’s not worth the risk.
Pros
Cons
Gastric bypass surgery cost typically includes fees for your surgeon, hospital stay, and anesthesiologist.Â
All or part of this cost may be covered by your health insurance, but some insurance carriers exclude all types of bariatric procedures. Whether your health insurance pays for the procedure will also depend on your current BMI and documented obesity-related health issues. If your insurance won’t cover gastric bypass surgery, there are financing options.
See our complete guide to gastric bypass surgery costs and insurance
The gastric bypass photos in our gallery have been shared by the provider who performed the procedure, with the patient's consent.
This surgery is generally safe when it’s performed by an experienced, board-certified bariatric surgeon. That said, it does come with risks of potential complications, including:
In rare cases, these complications can lead to death.
According to the Center for Metabolic and Weight Loss Surgery at Columbia University, “Operative complications such as bleeding or intestinal leakage can occur in less than 2% of patients.” Researchers cited a mortality rate of 0.5%, though the ASMBS reported in 2012 that the 30-day mortality rate for gastric bypass was 0.14%, compared to 0.08% for sleeve gastrectomy and 0.03% for gastric banding.Â
Talk with your doctor and weigh these risks against the risks that come with chronic obesity, which has about a 5% mortality rate.
Your life expectancy, health, and quality of life should improve significantly after a gastric bypass procedure. However, long-term side effects can include:
Talk with your surgeon about how to mitigate these potential side effects.
Abdominal pain can signal an internal hernia. According to research, this occurs most commonly “within two to three years after primary gastric bypass, often in the context of significant weight loss.” Most internal hernias can be repaired laparoscopically.
The ideal gastric bypass candidate has a body mass index (BMI) of 40 or greater. However, if your BMI is at least 35, you may still qualify for the surgery if you have at least one medical condition related to obesity, such as:Â
One study published in 2016 shows that gastric bypass surgery reduces the risk of dying from obesity and other related diseases by 48% for up to 10 years post-surgery.Â
A 2019 study in the journal Diabetologica suggests that gastric bypass can send type 2 diabetes into remission. Dr. Shawn Garber, a bariatric surgeon in Roslyn Heights, New York, explains that “the American Society for Metabolic and Bariatric Surgery [ASMBS] has recently lowered the qualifying criteria, saying that gastric bypass should be an option for people with a BMI of 30 to 35 if they also have type 2 diabetes.” Unfortunately, this criteria hasn’t yet been accepted by most insurance carriers.
To see whether you’re a good candidate for this weight-loss surgery, consult with a board-certified bariatric surgeon.
Here’s what you can expect in the lead-up to your procedure:
The procedure itself is typically performed in a hospital, under general anesthesia. Here’s how it works.
Doctors on RealSelf say you’ll need at least two and possibly three weeks of downtime after this procedure.Â
Here’s what to expect—and look out for—during that time.
Follow Up
Discomfort
A Liquid Diet
Light Exercise
Gastrointestinal Issues
Potential Hair Loss
Sagging Skin
Your surgeon will give you specific recommendations on exercise, but this is the typical guidance:
During the first year to year and a half after gastric bypass surgery, patients lose 70% of their excess weight, on average. That being said, some patients start gaining weight back within 12–18 months, degrading their initial results. According to the Cleveland Clinic, this is almost always related to diet.
The ASMBS says studies show that 90% of patients maintain at least 50% of their weight loss for up to two decades. Typically, maintaining 50% of your weight loss five years after surgery is considered a success.Â
Surgery is a tool, not a cure for obesity. Dr. Garber recommends that patients stick to a high-protein, low-carbohydrate diet and regular exercise regimen to lose weight and maintain their results. He also suggests avoiding carbs, sugar, and fatty foods and taking supplements, like vitamin B12, iron, and calcium regularly.
Beyond sheer weight loss, gastric bypass patients typically see their cardiovascular health, energy levels, and quality of life improve following surgery.
According to a 2011 study, infertility problems related to obesity tend to improve after significant weight loss from gastric bypass.
You can have a baby following gastric bypass surgery, although doctors strongly recommend waiting to become pregnant until after your weight has stabilized.Â
Pregnancy post-surgery is also not without risks: In one documented incident, midgut volvulus (a condition where the intestines become twisted during pregnancy) led to fatal sepsis in a 31 year-old woman who previously had Roux-en-Y gastric bypass surgery.
A sleeve gastrectomy, also called gastric sleeve surgery, is the most common type of bariatric surgery done today. It reduces the size of your stomach by about 80%, physically removing a part of the stomach from your body and leaving what remains in the shape of a narrow tube or sleeve.Â
Gastric sleeve surgery is similar to a laparoscopic gastric bypass, but it doesn’t involve bypassing the intestines, which may reduce the risk of complications.
Many bariatric surgeons prefer the sleeve to gastric bypass because it’s less invasive but still very effective. A whopping 98% of RealSelf members say their sleeve gastrectomy was “Worth It.”
Endoscopic sleeve gastroplasty (aka ESG) is also gaining popularity. Unlike a traditional sleeve gastrectomy, this minimally invasive, low-downtime, outpatient procedure does not remove a part of the stomach, but rather reshapes it to limit food consumption and calorie absorption.
An ESG involves guiding a tiny camera and endoscopic suturing device down your throat, into your stomach. By stitching a series of folds into the stomach, your surgeon reduces its size to about that of a banana, dramatically shrinking its capacity while slowing the transit of food to help patients feel full longer.
With an ESG, patients typically lose 15% to 20% of their total body weight after one year.
American Society for Metabolic and Bariatric Surgery staff, 10-year data shows gastric bypass patients significantly reduce risk of dying early from obesity and other diseases (2016)
American Society for Metabolic and Bariatric Surgery staff, Metabolic and Bariatric Surgery (2013)
American Society for Metabolic and Bariatric Surgery staff, Studies Weigh in on Safety and Effectiveness of Newer Bariatric and Metabolic Surgery Procedure (2012)
Baggesen L., Madsen L., Richelsen B., Thomsen R., Effect of Roux-en-Y gastric bypass surgery on diabetes remission and complications in individuals with type 2 diabetes (2019)
Cleveland Clinic staff, How to Keep the Weight Off After Bariatric Surgery (2019)
Columbia University Department of Surgery staff, Gastric Bypass Surgery (n.d.)
Diaz J., Kaunitz A., Kerwin A., Sanchez-Ramos L., Maternal death caused by midgut volvulus after bariatric surgery (2005)
Greenstein A., O’Rourke R., Abdominal Pain following Gastric Bypass: Suspects & Solutions (2011)
Kominiarek M., Preparing for and Managing a Pregnancy After Bariatric Surgery (2011)
Updated October 25, 2022