There are two steps during gastric bypass surgery:
The first step makes your stomach smaller. Your surgeon will use staples to divide your stomach into a small upper section and a larger bottom section. The top section of your stomach (called the pouch) is where the food you eat will go. The pouch is about the size of a walnut. It holds only about 1 ounce of food. Because of this you will eat less and lose weight.
The second step is the bypass. Your surgeon will connect a small part of your small intestine (the jejunum) to a small hole in your pouch. The food you eat will now travel from the pouch into this new opening into your small intestine. Because of this, your body will absorb fewer calories.
Gastric bypass can be done in two ways. With open surgery, your surgeon will make a large surgical cut to open up your belly. Your surgeon will do the bypass by working on your stomach, small intestine, and other organs.
Another way to do this surgery is to use a tiny camera, called a laparoscope. This camera is placed in your belly. The surgery is called laparoscopy.
In this surgery:
First, your surgeon will make 4 to 6 small cuts in your belly.
Then your surgeon will pass the laparoscope through one of these cuts. It will be connected to a video monitor in the operating room. Your surgeon will look at the monitor to see inside your belly.
Your surgeon will use thin surgical instruments to do your bypass. These instruments will be inserted through the other cuts.
Advantages of laparoscopy over open surgery include:
Shorter hospital stay and quicker recovery.
Smaller scars and a lower risk of getting a hernia or infection.
This surgery takes about 2 to 4 hours.
Why the Procedure Is Performed
You will usually not have weight-loss surgery unless you cannot lose a large amount of weight and keep it off by dieting, changing your behavior, and exercising alone.
Doctors often use the body mass index (BMI) and health conditions such as type 2 diabetes and high blood pressure to determine which patients are most likely to benefit from weight-loss surgery.
Gastric bypass surgery is not a "quick fix" for obesity. You must diet and exercise after surgery. You also need to know about the risks of surgery, and what your life will be like after the surgery.
Gastric bypass is major surgery and it has many risks. Some of these risks are very serious. You should discuss these with your surgeon. Risks for any surgery or anesthesia include:
Allergic reactions to medicines
Blood clots in the legs that may travel to your lungs
Heart attack or stroke during or after surgery
Infection, including in the cut, lungs (pneumonia), bladder, or kidney
There are a number of risks for any weight-loss surgery. There are also risks that are more likely after gastric bypass surgery.
Before the Procedure
Your surgeon will ask you to have tests and visits with other health care providers before you have this surgery.
If you are a smoker, you should stop smoking several weeks before surgery and not start smoking again after surgery. Smoking slows recovery and increases the risks of problems. Tell your doctor or nurse if you need help quitting.
Always tell your doctor or nurse:
If you are or might be pregnant
What drugs, vitamins, herbs, and other supplements you are taking, even ones you bought without a prescription
During the week before your surgery:
You may be asked to stop taking aspirin, ibuprofen (Advil, Motrin), vitamin E, warfarin (Coumadin), and any other drugs that make it hard for your blood to clot.
Ask your doctor which drugs you should still take on the day of your surgery.
Most people stay in the hospital for 3 to 5 days after surgery.
In the hospital:
You will be asked to sit on the side of the bed and walk a little the same day you had surgery.
You may have a (tube) catheter that goes through your nose into your stomach for 1 or 2 days. This tube helps drain fluids from your belly.
You may have a catheter in your bladder to remove urine.
You will not be able to eat for the first 1 to 3 days. After that, you can have liquids and then pureed or soft foods.
You may have a catheter connected to the larger part of your stomach that was bypassed. It will come out of your side and will drain fluids.
You will wear special stockings on your legs to help prevent blood clots from forming.
You will receive medicine through shots to prevent blood clots.
You will receive pain medicine. You will take pills for pain or receive pain medicine through an IV, a catheter that goes into your vein.
You will be able to go home when:
You can eat liquid or pureed food without vomiting.
You can move around without a lot of pain.
You do not need pain medicine through an IV or given by shot.
Most people lose about 10 to 20 pounds a month in the first year after surgery. Weight loss will decrease over time. By sticking to your diet and exercise from the beginning, you will lose more weight.
You may lose half or more of your extra weight in the first 2 years. You will lose weight quickly after surgery if you are still on a liquid or pureed diet.
Losing enough weight after surgery can improve many medical conditions, including:
Weighing less should also make it much easier for you to move around and do your everyday activities.
To lose weight and avoid complications from the procedure, you will need to follow the exercise and eating guidelines that your doctor and dietitian have given you.
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Joshua Kunin, MD, Consulting Colorectal Surgeon, Zichron Yaakov, Israel. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.