Roux-en-Y Gastric Bypass (RYGB) surgery

What is the Roux-en-Y gastric bypass?

During the surgery, the top of the stomach is removed and sealed off from the rest of the stomach. The resulting pouch is about the size of an egg and can only hold about 30ml of food. Before surgery, your stomach could hold about 1500mls of food. The surgeon then divides the small intestine and sews part of it directly onto the new stomach pouch. Food then goes into the small pouch of the stomach and then directly into the small intestine. The food has, therefore ‘bypassed’ most of the stomach and the first section of the small intestine which alters the production of certain gut hormones that control appetite and satiety. This reduces hunger and creates fullness quickly so the amount you can eat is much less. Sometimes people experience taste changes meaning that certain foods may taste different or become unappealing.

The operation usually takes two to three hours and is done under general anaesthesia, which means you will be asleep during the procedure. Gastric bypass is usually done using keyhole (laparoscopic) surgery. Patients are able to go home two to three days after the surgery but it usually takes between two to three weeks to make a full recovery from a gastric bypass operation.

A consequence of the surgery is that fewer vitamins and minerals are absorbed as food passes through the intestine. You will need to take vitamin and mineral supplements prescribed every day to prevent nutrient deficiencies. Regular blood tests are also essential to ensure you do not develop any nutritional deficiencies.



How does the Roux-en-Y Gastric Bypass work?

It promotes weight loss by: 

  1. decreasing the amount of food you can eat during meals.
  2. The balance of your gut hormone changes make you feel less hungry, reducing your desire to eat.
  3. Food digestion and absorption is reduced.
  4. It reduces the body’s fat set point, increasing sensitivity to leptin, making you feel full.


Expected weight loss

  • Much of the excess weight is lost over the first year after surgery. 
  • On average, people lose about 55 – 80% of their excess weight, although this varies from person to person. That is 55-80% of the extra weight you are carrying over and above your ideal weight for your height.
  • Studies show that a large number of patients kept at least 60% of the excess weight off 5 years after surgery. 
  • Bariatric surgery reduces the risk of heart disease, stroke and death from obesity.
  • The gastric bypass procedure is particularly effective at reducing your medication for type 2 diabetes and many people can come off medications for type 2 diabetes altogether.
  • Many other obesity-related conditions such as obstructive sleep apnoea, high blood pressure and joint pains are either completely resolved or substantially improved following surgery.
  • Long-term sustained weight loss and improvement in obesity-related health conditions will only occur with healthy eating and regular exercise.


Things to consider

  • The amount of food you can eat is reduced. It is therefore important to eat a healthy, balanced and varied diet for a healthy body
  • It is important to remember the operation will not stop you from craving certain foods or eating what you fancy
  • Nausea and vomiting may occur. particularly in the first few days after surgery; vomiting is common if you eat too much too quickly or do not chew properly.
  • You will need to take multivitamin and mineral supplements daily to avoid nutritional deficiencies
  • RYGB carried a higher risk of death and early complications requiring a reoperation compared with the sleeve gastrectomy
  • Some people experience hair thinning; this is usually temporary and associated with weight loss in the first few months.
  • 30% of patients experience ‘dumping syndrome’;, a condition that occurs if you consume too much sugar or alcohol. It is not considered a health risk but can be very unpleasant with symptoms including nausea, vomiting, diarrhoea, sweating, faintness, weakness and increased heart rate.


What are the advantages of a Roux-en-Y gastric bypass

  • It is the gold standard of bariatric surgery – it is the operation with which all other weight loss procedures are compared. It produces sustainable long-term weight loss in most patients.
  • Excess weight loss is greater than with a sleeve gastrectomy and weight rate regain is less common
  • It has a high and fast remission rate for type 2 diabetes. Up to 75% of people can come off or significantly reduce the medication straight after surgery.


What are the risks of this surgery? 

As with all major surgery, RYGB has some risks. These risks vary according to your age and other illnesses you may have, but up to 10% of people may have a complication following surgery. For most people, the benefits in terms of losing excess weight are much greater than the disadvantages of experiencing any discomfort. The table below summarises the risks specific to having a RYGB procedure:


In summary

The Roux-en-Y gastric bypass is an effective tool which can help you lose at least half of your excess weight and improve diseases related to obesity such as type 2 diabetes, high blood pressure, sleep apnoea and asthma. However, if a healthy lifestyle is not followed there is a risk of weight regain. Although there are risks associated with the surgery, in people with severe obesity, the benefits usually outweigh the risks. The operation will change the amount that you can eat on a permanent basis and should not be regarded as reversible. You are advised to do as much research as you can and perhaps speak to the people who have had surgery about their lifestyle after surgery so you can make an informed decision about whether surgery is a right treatment for you.