Patient education: Gastric bypass (The Basics)

What is a gastric bypass? — This is a type of weight loss surgery. For gastric bypass, the doctor closes off part of the stomach, leaving only a small pouch for food. Then, they connect the pouch to the middle part of the small intestine. This allows food to "bypass," or go around, part of the stomach and small intestine.

The two kinds of gastric bypass are:

●Roux-en-Y gastric bypass ("RYGB") (figure 1) – The stomach pouch is connected to the divided small intestine.

●One-anastomosis gastric bypass ("OAGB") (figure 2) – The stomach pouch is connected to a loop of undivided small intestine.

There are other weight loss surgeries that work like gastric bypass.

Gastric bypass surgery is most often done as a "minimally invasive" surgery. Minimally invasive surgery lets the doctor make smaller cuts, or "incisions," in the skin. They insert long, thin tools through the incisions. One of the tools has a camera (called a "laparoscope") on the end, which sends pictures to a TV screen. The doctor can look at the screen to see inside the body. Then, they use the long tools to do the surgery. They can control the tools directly, or with the help of a robot (this is called "robot-assisted" surgery).

Less often, this surgery can be done as an "open" surgery. During open surgery, the doctor makes a larger incision in the skin. This lets them see directly inside the body when they do the surgery.

You might be able to return to normal activities sooner if you had minimally invasive surgery than if you had an open surgery.

How do I prepare for gastric bypass surgery? — The doctor or nurse will tell you if you need to do anything special to prepare. Before surgery is scheduled, most people meet with a mental health professional and a dietitian. (A dietitian is an expert on food and eating.)

Before your procedure, your doctor will do an exam. They might send you to get tests, such as:

●Blood tests

●Imaging tests – Imaging tests create pictures of the inside of the body.

●Electrocardiogram ("ECG") – This test records your heart rate and rhythm.

Your doctor might want you to eat a low-calorie liquid diet for 1 to 4 weeks before your surgery. This will help make your liver smaller and softer and make the surgery easier.

Your doctor will also ask you about your "health history." This involves asking you questions about any health problems you have or had in the past, past surgeries, and any medicines you take. Tell them about:

●Any medicines you are taking – This includes any prescription or "over-the-counter" medicines you use, plus any herbal supplements you take. It helps to write down and bring a list of any medicines you take, or bring a bag with all of your medicines with you.

●Any allergies you have

●Any bleeding problems you have – Certain medicines, including some herbs and supplements, can increase the risk of bleeding. Some health conditions also increase this risk.

You will also get information about:

●Eating and drinking before your procedure – You will need to "fast" on the day of surgery to empty your stomach for anesthesia. This means not eating or drinking anything for a period of time. The staff will tell you when to stop eating and drinking.

●Lowering the risk of infection – In some cases, you might need to trim (not shave) your body hair before your procedure. You might also need to wash the area with a special soap.

●What help you will need when you go home – For example, you might need to have someone else bring you home or stay with you for some time while you recover.

Ask the doctor or nurse if you have questions or if there is anything you do not understand.

What happens during gastric bypass surgery? — When it is time for the procedure:

●You will get an "IV," which is a thin tube that goes into a vein. This can be used to give you fluids and medicines.

●You will get general anesthesia. This makes you unconscious so you can't feel, see, or hear anything during the procedure. You might also get a breathing tube to help you breathe.

●The doctors and nurses will monitor your breathing, blood pressure, and heart rate during the procedure.

●The doctor will make a small pouch out of your stomach. Then, they will connect your small intestine to the stomach pouch. This lets digestive juices mix with the food in a shorter length of intestine, which leads to weight loss.

●The doctor will close your incisions and cover them with clean bandages.

●The procedure usually takes about 2 hours.

What happens after gastric bypass surgery? — After your procedure, you will be taken to a recovery room. The staff will watch you closely as your anesthesia wears off. Most people stay in the hospital for a day or 2 after surgery.

As you recover:

●You might feel groggy or confused for a short time. You might also feel nauseous or vomit. The doctor or nurse can give you medicine to help with this.

●You might have a sore throat from the breathing tube. This usually gets better quickly.

●The staff will help you get out of bed and start moving around when you are ready.

●You will get medicine if needed to help with pain. You might need other medicines, too.

●When you are allowed to eat, you will start with small amounts of clear liquids. The doctor will give you a specific eating plan. It will include the type and amounts of foods and liquids you can have.

What are the risks of a gastric bypass? — Your doctor will talk to you about all of the possible risks, and answer your questions. Possible risks include:

●Bleeding

●Infection inside the belly or at the incision

●Leaks from the incision or from the connection of the stomach or intestine

●A blockage, narrowing, or tear in the stomach or intestine

●Problems with the heart or lungs, including blood clots

●Low blood sugar

●Problems with how the body absorbs nutrients

●Severe diarrhea, flushing, and cramping after eating

●Needing more surgery

What else should I know? — Before you go home from the hospital, make sure that you know what problems to look out for and when you should call the doctor. Make sure that you understand your doctor's or nurse's instructions, especially about what you are allowed to eat and drink. Ask questions about anything you do not understand.

More on this topic

Patient education: Gastric bypass – Discharge instructions (The Basics)
Patient education: Weight loss surgery (The Basics)
Patient education: Care after weight loss surgery (The Basics)
Patient education: Diet after weight loss surgery (The Basics)

Patient education: Weight loss surgery and procedures (Beyond the Basics)