Gastric Band Bypass

A gastric bypass is the alternative surgical procedure to a gastric band surgery. Gastric bypass surgery works by decreasing the size of your stomach and making your digestive system shorter. This means patients not only feel full on small portions of food but it also means less food is absorbed into the body.   

Before the operation


Before the operation patients will meet with the surgeon who will ask them to start preparing for the surgery. This will include:

  • Stopping smoking as smoking will increase the chance of infection, and slow down recovery.
  • Fasting. The surgeon will ask the patient to not consume and food or drink for up to six hours before the procedure.
  • Before the procedure a nurse will ask the patient to sign a consent form. This confirms the patient has given permission for the operation to go ahead and that they also understand about the alternative procedures and the risks involved with the bypass.
  • The patient’s blood pressure, heart rate and urine will all be checked by a nurse.
  • The patient may also be required to wear compression stockings to prevent the chance of a blood clot. An anti clotting medicine may also be given.

The operation


The gastric bypass operation is performed under general anaesthesia and usually requires a two to four day stay in hospital. During the operation the surgeon uses surgical staples to separate the top part of the patient’s stomach from the rest of it. A section of the small intestine is then bypassed and connected with the “smaller” stomach. This enables less food to be digested by the body as it takes a shorter route through the digestive system. The operation can take between one and three hours depending on whether the surgeon performs laparoscopic surgery or open surgery. 

The risks

Gastric bypass surgery is a commonly performed operation with few complications although patients do need to understand the possible risks involved with the operation. The main complications include:

  • Infection. Antibiotics are used to prevent this.
  • Damage to any other organs in your abdomen. If this happens the patient may require further surgery to correct any problems.
  • Bowel leak. Further surgery may be required to repair where the surgeon has joined the patient’s stomach to the small intestine if it is leaking in the first few days after the initial surgery.
  • Weight problems. There is a chance of gallstones if weight is lost too rapidly but there is also a chance that no weight will be lost at all.
  • There may also be an unpleasant sensation after surgery called ‘dumping’. This means the patient may start to feel faint and queasy if they try to eat a large amount of sugary food.

After surgery

Full recovery from a bypass operation can take up to six weeks, although like with the risks this is different for each individual. After surgery rest is required until the effects of the anaesthetic have worn off. The patient will then be encouraged to get out of bed and move around to prevent the chance of blood clots forming. Pain killers may be prescribed to deal with any discomfort. 

On the first day after surgery patients may have a catheter bag to drain the bladder and also some fine tubes running from the wound. These are used to drain any fluid and are usually removed after two days. On the second day patients will have an x-ray to check that the bypass operation has worked and to check there is no leakage. Following this the surgeon will advise on a diet whilst you recover and further lifestyle and diet changes for the long term. After around four days patients are usually allowed to return home.

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