Gastric Bypass Surgery

Gastric bypass surgery, also called the Roux-en-Y gastric bypass procedure, is the most common form of weight loss surgery performed in the United States today.

What is Gastric Bypass Surgery?

About Gastric Bypass Surgery

Also known as stomach bypass surgery or bariatric bypass surgery, this procedure creates a small pouch that bypasses the stomach and attaches to the intestine. A gastric bypass operation is irreversible, in most cases.


Your bariatric surgeon will perform gastric bypass surgery either:

  • Laparoscopically, making several small 1/4- to 1/2-inch abdominal incisions.
  • Traditionally as an “open” procedure, making one 10- to 12-inch abdominal incision.
How you lose weight: Restricts the amount of food you can eat and reduces the number of calories your body will absorb.
Weight loss: Weight loss is rapid. Expect to lose 60 to 80 percent of excess body weight within 12 to 18 months after surgery.
Surgery time: 1.5 hours.
Hospital stay: Two to three days.
Recovery time: About two weeks.

What to Expect: Gastric Bypass Weight Loss Surgery

Here's what to expect if you're considering stomach bypass surgery.

During gastric bypass surgery

After you receive general anesthesia, your bariatric surgeon will:

  • Assess the abdomen and then use surgical staples to create a small pouch at the top of your stomach.
    • This pouch — which over time can hold about one cup of food — will be your new, smaller stomach.
    • A normal stomach can hold more than four to six cups of food.
  • Cut the small intestine and attach it to the new pouch.
    • With the intestinal bypass, food will now move from the new stomach pouch to the middle section of the small intestine.
    • It will bypass the lower stomach and the upper section of the small intestine.
  • Attach the upper section of the small intestine to the middle section of the small intestine.
    • This will allow digestive fluids, that the lower stomach makes, move down the upper section of the small intestine and into the middle section.
  • Close the incisions with staples or stitches.

After gastric bypass bariatric surgery

  • You can expect to stay in the hospital for two to three days.
  • The morning after your gastric bypass surgery, you will:
    • Start a clear liquid diet for at least two weeks. It's very important that you drink at least 64 ounces of fluid every day to avoid becoming dehydrated.
    • Begin to go for walks around your room and in the halls.
  • Immediately before discharge, your bariatric surgery team will give you instructions on how to care for yourself at home, including:
    • Incision and drainage care
    • Pain control
    • Vitamin supplements to get adequate amounts of vitamin B12, iron, and calcium

Dumping Syndrome and Other Risks of Gastric Bypass Surgery

Dumping syndrome is a potential risk of gastric bypass surgery. It occurs when large volumes of food in the stomach move too quickly through the small intestine, frequently after eating sweet or high-fat foods.

Dumping syndrome can cause:

  • Nausea
  • Vomiting
  • Cramps
  • Diarrhea
  • Sweating
  • Dizziness
  • Weakness

Other risks and complications of gastric bypass surgery include:

  • Perforation of stomach or intestines
  • Leakage of surgical connection between the stomach and the intestine
  • Internal bleeding or profuse bleeding of the surgical wound
  • Gastric pouch/anastomotic obstruction or bowel obstruction

Your bariatric surgeon will review all potential gastric bypass risks, complications, and other weight loss surgery options with you prior to your procedure. If you have any questions about gastric bypass surgery, we encourage you to ask your surgeon.

» Learn more about what to expect after gastric bypass surgery.


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