What is a gastric bypass?
Gastric bypass or “Roux-en-Y” gastric bypass surgery combines restriction and an effect on gut hormones to deliver long-term weight loss.
The procedure involves dividing the stomach and the bowel but despite being more invasive than gastric banding, in expert hands it is a safe, very effective form of weight loss surgery.
Is a gastric bypass suitable for me?
Your eligibility for a gastric bypass procedure is based on a number of factors including your weight and medical history but as a general rule, it could be suitable for you if…
- You have a BMI of 40kg/m2 or over
- You’ve tried and failed with diets and know that you need a permanent solution
- You couldn’t comply with the lifestyle changes of a gastric band
- You suffer with co-morbidities eg Type 2 diabetes and hypertension
How will it help me lose weight?
It used to be believed that gastric bypass led to significant calorie malabsorption, ie. calories from food and drink could not be absorbed across the wall of the bypassed section of small bowel. This is not the case. Studies have shown that although an element of calorie malabsorption is present early after surgery, this is relatively short-lived. Instead, it seems that gastric bypass has a major impact on various gut hormones, some of which are involved in appetite regulation.
So how does it work?
- Restriction: The new small pouch represents only about 5% of the total stomach volume which means you can only eat a very small amount of food before feeling full
- Effect on gut hormones: Levels of the appetite stimulant ghrelin fall after gastric bypass, which may explain why patients experience such a marked loss of appetite. Patients also see profound changes in taste and food preferences, which may further contribute to weight loss
How much weight will I lose?
We expect a gastric bypass patient to lose 60-70% of their excess weight in the first 2 years with most weight loss in the first year). Naturally some people will lose more and others a little less than this.
What does the procedure involve?
The gastric bypass procedure is performed laparoscopically (“keyhole” surgery) under general anaesthetic and takes around 1-2 hours. It usually involves a two night stay in hospital. Most patients will take a few days to recover and we advise taking 1-2 weeks off work (depends on the nature of your work).