Gastric Bypass FAQ

The gastric bypass is one of the most common weight loss procedures. The following gastric bypass FAQs will help you learn more about this treatment.

How much weight will I lose?

The national average weight loss following a gastric bypass is 60-70% of excess body weight over a 12-18 month period. Weight loss is generally quite fast initially but will settle into a regular pattern.

Will I lose weight quickly?

Weight loss commences when the liver reducing diet is introduced prior to surgery. Post operative weight loss can be quite rapid in the first six to eight weeks but then will settle into a steady monthly reduction until around 18 months. Long-term success is related directly to a patient’s motivation and their commitment to following the dietary guidelines provided.

How long will I have to stay in hospital after surgery?

You will normally stay in hospital for two nights for this type of procedure. The first night you will be in a High Dependency Unit.

Will I have to take any medication after surgery?

Yes. All gastric bypass patients will need to take protein pump inhibitor for 3 months to protect the stomach. Nutritional supplements will need to be prescribed by your GP to commence six weeks after your operation. These medications will be discussed during your consultation and pre-assessment prior to surgery.

How will my diet change after surgery?

It is vital that only liquids are consumed for the first two weeks to reduce the risk to the stitches healing in the stomach. Then there is a need to restrict the consistency and type of foods that can be consumed in order to progress the healing and because of the presence of swelling between the opening of the new stomach pouch and the intestine. The new stomach pouch is much smaller and subsequently has a smaller capacity to store anything that you eat. This means you won’t be able to eat large volumes of food. You will feel full very quickly (after only a few teaspoons initially) and your appetite should decrease. As the body adjusts and swelling settles there will be some give allowing for more solid food to be consumed.

You will not be able to eat the same volume of food as you do now. By the end of the first year you should be able to eat a child sized portion of food. This will gradually increase as your weight stabilizes and your tolerance increases.

Due to dietary restrictions it is important to protect against nutritional deficiencies. Following surgery you should have a multivitamin, calcium and iron supplement that will protect against the risks of osteoporosis and anaemia. Occasionally a zinc deficiency may occur and you may be prescribed a further supplement. An anti-acid tablet will help reduce stomach acid and prevent the formation of ulcers. Immediately following surgery, the body is healing, so it is important that you still consume adequate calories and protein to help promote recovery.

What if I am still very hungry after surgery?

Most patients experience a reduction in hunger following a gastric bypass though some patients continue to feel hungry at times. It is important to make lifestyle changes and change eating habits to best manage those symptoms. ‘Head hunger’ and ‘stomach hunger’ can be different and it is important to learn to recognise the difference at the early stages. Habit and food dependence may need to be addressed to reduce those symptoms.

What are the potential complications of surgery?

Possible risks for gastric bypass surgery include, but are not limited to:

General Complications:

  • Allergic Reactions: From minor reactions such as rash to sudden overwhelming reactions
  • Anaesthetic Complications: Anaesthesia used to put you to sleep for the operation can be associated with variety of complications. The anaesthetist will discuss anaesthetic risks with you
  • Bleeding: From minor to massive bleeding that can lead to the need for blood transfusion and/or emergency surgery
  • Blood Clots: Also called deep vein thrombosis (DVT) and pulmonary embolus (PE) that can sometimes cause stroke, heart attack, loss of limb and death
  • Infection: Including wound infections, bladder infections, pneumonia and deep abdominal infections

Specific Complications:

  • Leak: After operations bypass the stomach, the new connection can leak stomach acid, bacteria and digestive enzymes causing severe infection and abscess. This can require repeated surgery and intensive care admission
  • Narrowing (stricture): Narrowing of the connection between the stomach and the small bowel can occur after the operation. This may require endoscopic dilatation or re-operation
  • Dumping Syndrome; Symptoms of the dumping syndrome include cardiovascular problems with weakness, sweating, nausea, diarrhoea and dizziness can occur in some patients after gastric bypass
  • Bowel Obstruction: Any operation in the abdomen can leave behind scar tissue that can put the patient at risk for later bowel blockage
  • Laparoscopic surgery risks: Laparoscopic surgery uses punctures to enter the abdomen and can lead to injury and bleeding
  • Hernia; Cuts in the abdominal wall can lead to hernias after surgery. Hernia(s) can happen internally after surgery due to mobilisation of bowel and can cause bowel obstruction
  • Hair loss: Many patients develop hair loss for a short period after surgery. This usually responds to increased levels of vitamins
  • Vitamin and Mineral Deficiencies: After gastric bypass there is a malabsorption of many vitamins and minerals. Patients must take vitamin and mineral supplements forever to protect themselves from these problems
  • Complications of Pregnancy: Vitamin and mineral deficiencies can put the newborn babies of gastric bypass mothers at risk. No pregnancy should occur for the first 12-18 months after surgery. Patients must be certain not to miss any of their vitamins if they decide to go ahead with pregnancy later
  • Ulcers: Patients undergoing gastric bypass may develop ulcers at the pouch, the bottom of the stomach or parts of the intestine. Ulcers may require medical or surgical treatment and have complications of chronic pain, bleeding and perforation

Can the surgery be reversed?

No, it is vital that a lifetime commitment is made by the patient prior to proceeding to surgery.