What is Gastric Bypass Surgery and How Does It Work?

Designed to reduce the size of the stomach and to bypass part of the small intestine, Roux-en-Y gastric bypass surgery uses a combination of restriction and malabsorption.

This procedure is considered the gold standard in bariatric surgery. During the procedure, the surgeon creates a smaller stomach pouch. The doctors then attaches a Y-shaped section of the small intestine directly to the pouch. This allows food to bypass a portion of the small intestine, which absorbs calories and nutrients.

The Roux-en-Y gastric bypass surgery affects weight loss in two ways: 1) the smaller stomach pouch restricts food intake and 2) bypassing a portion of the small intestine means that calories are absorbed to a lesser extent.

What Are the Benefits of Gastric Bypass Surgery?

  • Rapid weight loss. Patients lose an average of 70% of excess body weight within 12 to 18 months after surgery.
  • Proven long-term track record. Studies show that 10 to 14 years after surgery, patients have maintained an average loss of 60% of their excess weight.
  • Reduced co-morbidities. The procedure significantly reduces, and sometimes, even eliminates conditions related to obesity, including high blood pressure, Type II diabetes and sleep apnea. Type 2 diabetes is often resolved even before ideal weight loss is achieved.
  • Reduced desire to eat. Patients report that they feel fuller faster and achieve satiety - the feeling of being satisfied - with less food; therefore, overeating is less likely to occur.

Health Benefits

Studies found that gastric bypass:

  • Resolved type 2 diabetes in 83.8% of patients and often resolved the disease within days of surgery.
  • Resolved high blood pressure in 75.4% of patients.
  • Improved high cholesterol in 95% of patients.

Quality of Life

One meta-analysis stated that for bariatric surgery patients who experienced significant weight loss:

  • Overall quality of life improved greatly.
  • They experienced improved physical functioning and appearance.
  • They experienced improved social and economic opportunities.

How is Gastric Bypass Surgery Performed?

Gastric Bypass Roux-en-Y surgery is performed laparoscopically. During the laparoscopic procedure, six small incisions are made and surgeons use specialized instruments and a tiny camera to perform the surgery.

For more information about outcomes, read the article "Outcomes After Laparoscopic Roux-en-Y Gastric Bypass for Morbid Obesity" on the U.S. National Library of Medicine website.

What Are the Potential Risks of Gastric Bypass Surgery?

Potential complications can include leaks at the connection sites of the pouch and small bowel; infection; small bowel obstruction; internal hernia; pulmonary embolus and even death. Patients can avoid vitamin and mineral deficiencies with proper supplementation, and our staff is there to ensure that nutritional levels are regularly monitored. A condition known as dumping syndrome can occur from eating high-fat, high-sugar foods. While it isn't considered a health risk, the results can be very unpleasant and may include vomiting, nausea, weakness, sweating, faintness, and diarrhea. Dumping can also be viewed as a positive side effect to your surgery. Dumping will actually enhance your weight loss efforts by discouraging you from eating high fat, high sugar foods.

You must supplement your diet with a daily multivitamin and calcium. You may also need to take vitamin B12 and/or iron.

A requirement to this surgery is that it is difficult to view the remaining portion of your stomach. If there are problems after surgery such as ulcers, bleeding, or malignancy, the stomach, duodenum, and parts of the small intestine cannot be seen easily using X-ray or endoscopy.

Gastric Bypass Surgery Recovery

One study found that gastric bypass patients were able to:

  • Leave the hospital after two days
  • Return to work 10-14 days after surgery

Patient Success Stories

  • NewStart patient, Cherie Evans, poses with her family.

    Cherie's Story: Weight Loss Surgery Helps Grateful Mom Overcome Infertility

    August 22, 2023

    Cherie Evans’ road to motherhood took some bumps and twists and turns. But the 32-year-old resident of Angleton, Texas, looks back on her journey with gratitude. For in her quest to give birth to a new life, she enriched—and potentially saved—her own.

    Read More
  • Becky Anton

    Becky Anton's Weight Loss Surgery Story

    December 22, 2016

    Kindergarten Teacher Becky Anton and her bariatric surgeon decided to pursue gastric bypass after discovering pre-cancerous cells in her esophagus. The procedure has not only relieved the discomfort in her esophagus, but her weight loss journey has renewed her spirit and her health.

    Read More
  • Read about Making Better Decisions After Surgery

    Making Better Decisions After Surgery

    May 2, 2013

    Katia was having trouble doing exercise, going on bike rides with her kids and having problems with her back. She is young, has three beautiful children and a wonderful husband, and she wanted to get healthy. For her situation, gastric bypass would yield the best results. Bypass is a two componen...

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  • Read about Weight Loss Surgery Cured Heartburn

    Weight Loss Surgery Cured Heartburn and Hiatal Hernia Complications

    May 1, 2013

    By May 2010, seven months after the surgery, she achieved a major victory and her weight had dropped from a preoperative high of 251 to between 180 and 185; and she's still losing. Asthma, which she's had all her life, no longer plagues her. Her knees are improving, she no longer sleeps with the ...

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  • Read about Diabetes-Free After Weight Loss Surgery

    Diabetes-Free After Weight Loss Surgery

    May 1, 2013

    Gwen began having problems with her weight after the birth of her first child. Before her pregnancy she weighed 125 pounds but by the time she delivered, she had jumped to 299, a weight she maintained during her second pregnancy and delivery. She developed type 2 diabetes, urinary incontinence an...

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