Gastric bypass is surgery that is done to help you lose weight. After the surgery, you will not be able to eat as much as before, and your body will not absorb all the calories from the food you eat.
This surgery helps you lose weight by changing how your stomach and small intestine handle the food you eat.
After the surgery, your stomach will be smaller. You will feel full or satisfied with less food.
The food you eat will no longer go into some parts of your stomach and small intestine that break down food. Because of this, your body will not absorb all the calories from the food you eat.
You will receive general anesthesia before this surgery. This will make you unconscious and unable to feel pain.
Gastric bypass can be done in 2 ways. In open surgery, your surgeon will make a large incision (cut) to open up your belly. Your surgeon will do the bypass by directly handling your stomach, small intestine, and other organs.
Another way to this surgery is to use a tiny camera, called a laparoscope, which is placed in your belly. This is called laparoscopy. In this surgery:
First, your surgeon will make 4 to 6 small incisions in your belly.
Then your surgeon will pass the laparoscope through one of these incisions. 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 incisions.
You will probably stay in the hospital a shorter time and recover more quickly after laparoscopy, compared to open surgery. There are also fewer incision problems after this surgery. You will also have smaller scars and a lower risk of developing hernias after laparoscopic surgery.
Laparoscopy may not be safe for you if you:
Have had abdominal surgery in the past. This is because you may have scar tissue from earlier surgery.
Have severe heart and lung disease
Weigh more than 350 pounds
There are 2 basic steps during both kinds of gastric bypass:
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 the stomach (called the pouch) is where the food you eat will go. This pouch is about the size of a walnut. It holds only about 1 ounce of food.
The second step is the bypass. Your surgeon will connect a part of your small intestine, called the jejunum, to a small hole in your pouch. The jejunum is farther down from where your stomach normally attaches to your small intestine. Food you eat will now travel from the pouch into this new opening into your small intestine. When food travels this way, it bypasses the lower part of your stomach and the first part of your small intestine. Because of this, your body will absorb fewer calories.
This surgery takes about 4 hours.
This surgery may increase your risk for gallstones. Your doctor may recommend having a cholecystectomy (surgery to remove your gallbladder) before your bypass surgery.
Weight-loss surgery may be an option if you are very obese and have not been able to lose weight through diet and exercise.
Gastric bypass surgery is not a "quick fix" for obesity. You must be committed to diet and exercise because you must continue dieting and exercising after the surgery. You may have complications from the surgery if you don’t. One problem some people have is throwing up if they eat more than their new small stomach can hold.
People who have this surgery should be mentally stable and not be dependent on alcohol or illegal drugs.
This procedure may be recommended for you if you have:
A body mass index (BMI) of 40 or more. Someone with a BMI of 40 or more is at least 100 pounds over their recommended weight. A normal BMI is between 18.5 and 25.
A BMI of 35 or more and a serious medical condition that might improve with weight loss. Some of these conditions are sleep apnea, type 2 diabetes, and heart disease.
Vomiting from eating more than your stomach pouch can hold
Dumping syndrome. This is when the contents in your stomach move through your small intestine quickly. This causes discomfort and poor nutrition.
Incisional hernia, which is much more common when an open procedure is done. An incisional hernia is a bulging of tissue through the site of your incision.
Your surgeon will ask you to have tests and visits with your other health care providers before you have this surgery. Some of these are:
A complete physical exam
Blood tests, ultrasound of your gallbladder, and other tests to make sure you are healthy enough to have surgery
Visits with your doctor to make sure other medical problems you may have, such as diabetes, high blood pressure, and heart or lung problems, are under control
Nutritional counseling
Classes to help you learn what happens during the surgery, what you should expect afterward, and what risks or problems may occur afterward
Visiting with a mental health provider to make sure you are emotionally ready for major surgery. You must be able to make major changes in your lifestyle after 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.
Prepare your home for after the surgery
On the day of your surgery:
Do not eat or drink anything after midnight the night before your surgery.
Take the drugs your doctor told you to take with a small sip of water.
Your doctor or nurse will tell you when to arrive at the hospital.
Most people lose about 10 to 20 pounds a month in the first year after surgery. Weight loss will decrease over time, so sticking to your diet and exercise early on will provide the largest weight loss. You may lose half or more of your extra weight in the first 2 years. You will lose weight most quickly just after surgery, when you are still on a liquid diet or pureed diet.
Weighing less should also make it much easier for you to move around and do your everyday activities.
Bypass surgery alone is not a solution for weight loss. It can train you to eat less, but you still have to do much of the work. To lose weight and avoid complications from the procedure, you will need to follow the exercise and eating guidelines that your doctor and dietitian gave you.
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Update Date:
2/12/2009Updated by:
Crystine Lee, MD, Department of Surgery, Marin General Hospital, Greenbrae, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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