Laparoscopic Gastric Bypass

Gastric bypass is a type of weight loss surgery that involves making the stomach smaller and attaching a small part of the intestine directly to the reduced stomach. With this procedure patients are able to consume less food and absorb fewer calories, resulting in weight loss. Gastric bypass surgery can be done with open surgery or laparoscopy.

Indicators for Surgery

  1. Patients approximately 45 kilograms (100 pounds) heavier than their ideal body weight, which is equal to a BMI (body mass index) for 40 kg/m2.
  2. Patients with BMI of 35 kg/m2 and more with existing medical complications, such as diabetes, heart disease, hypertension, sleep apnea, and joint pain due to excess body weight.

Benefits of Surgery

Gastric bypass surgery reduces the size of the stomach and thus patients not only eat less, but are less hungry as well and feel full much more quickly. This controls caloric intake and results in effective weight loss.


A laparoscope is a thin, flexible fiberoptic instrument that is inserted into the body through small incisions. In a gastric bypass surgery, five small incisions, measuring between 0.5 to 2 centimeters, are made on the abdomen. The stomach is then divided into two sections with an inflatable silicone device called a gastric band, reducing it to just 15 to 30 milliliters. Part of the small intestine is then attached to this “pouch.”

Possible Complications

Since gastric bypass surgery is performed using anesthesia, it carries the same risks as any other surgery. Long-term complications tend to be related to the gastric band. The band may move or become dislodged. It may also grow into the stomach (band erosion). There is a 10 to 30% chance of these complications occurring.

Preparing for the Procedure

  • Before surgery the patient must undergo a health screening and an endoscopy to inspect the stomach to ensure they are healthy enough for the procedure.
  • The patient must attend a consultation with a dietician.
  • The patient must undergo a psychological assessment to ensure that they are willing to make the necessary lifestyle changes required after the surgery.
  • If applicable, the patient’s current medical conditions, such as diabetes, hypertension, heart disease and lung disease, will be assessed and controlled before the surgery.
  • If the patient smokes they must stop doing so at least two to three weeks before surgery and after surgery as it can hamper recovery and increase the risk of complications.
  • The patient should inform their doctor or the nurses if they think they might be pregnant.
  • The patient should inform the doctor of all medications and supplements (including herbal ones) that they are taking for recommendations on which ones may have to be stopped before the procedure.
  • Avoid food and water after midnight of the day of the surgery or as recommended by the doctor. If the patient must take medication (with the doctor’s permission), they may sip a little water.

Post-Procedure Instructions

  • After the surgery the patient will be moved to a recovery room. An oxygen mask may be placed to help with breathing. The patient will probably feel a little sleepy after waking up from the anesthesia. An IV will be in place to deliver fluids intravenously until the patient is able to eat. While in the recovery room the nurse will regularly check the patient’s pulse and blood pressure. The patient will be moved into their room once their condition improves. If the patient feels any nausea, they should inform the nurse immediately.
  • Usually the patient will remain in the hospital for three days, but this may change depending on the patient’s recovery. If any complications occur or additional surgery is needed, the patient will have to remain in the hospital longer.
  • After the surgery, the patient must begin controlling their diet immediately. This is an extremely important aspect of this procedure. A detailed eating plan will be created by the doctor and the patient must also see a dietician. The following are some basic principles that the patient will usually have to follow:
    • For the first four weeks after the surgery the patient will have to consume a liquid diet, such as broth, tea, coffee, drinks that do not contain sugar or are carbonated, vegetable and fruit juices, and yogurt. The patient must limit the amount of water consumed at one time and small, frequent meals are recommended.
    • For the next two weeks the patient can eat small pieces of food, such as rice soup, before transitioning to normal food. Meals should be small and food should be chewed thoroughly and longer than normal before it is swallowed. It is not recommended that water be drunk during meals, but instead can be drunk 15 to 30 minutes before eating.
  • The patient will receive details regarding the surgery and will have to return to see their doctor to follow up on the results of the procedure. The doctor will schedule regular appointments. Please remember that lifestyle modifications are essential for successful weight loss and maintenance after surgery.

Post-Surgery Diet

  1. Eat three meals a day and limit snacks between meals. Whether or not a patient loses weight will depend on what they eat. Snacks with no nutritional value, such as potato chips and sweets, and eating too frequently (thus consuming more calories than the body needs) will result in weight gain.
  2. Eat slowly and chew thoroughly. Not chewing food well can cause stomach pain, nausea, and vomiting and may irritate the stomach. It is very important that patients cut food into small people and chew until food is in liquid form before swallowing. Take short breaks between bites. A meal should last at least 30 minutes.
  3. Avoid sugar. Patients should not consume any food that lists “sugar” as the first ingredient. It is very important to read labels and notice how much sugar is in food and how much of that is natural or added. Patients should limit their sugar intake to 15 grams or less per meal to control caloric intake.



Surgical Clinics
Bumrungrad International Clinic (BIC) Building, 16th floor
Bumrungrad International Hospital, Bangkok, Thailand

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