Gastric sleeve
Often a first choice for people who want to feel full on smaller portions with a simpler operation. Usually not advised where there is a history of reflux or heartburn.
Sleeve
Bypass
MagDI™New
Sleeve or bypass? Find out which suits you.
Compare the gastric sleeve, the gastric bypass and MagDI™, the new bypass made with magnets, in plain words. Then let Dr John Loy, who performs all three, help you choose.
You do not need to decide before you talk to us. That is what the assessment is for.
Dr John Loy performs all three, with almost 3,000 weight loss procedures.
Trustpilot 4.8 from 452 reviews
25 years caring for patients in Ireland
40,000+ patients
Accredited private hospital in Dublin
Free consultation, no long waiting list
Side by side, in plain words
Sleeve, Bypass And MagDI™ Compared
Auralia performs all three, and none of them is right for everyone. Here is how they differ.
Follow one option:
All three are keyhole operations under general anaesthetic, performed at Auralia Private Hospital in Dublin.
Gastric sleeve
A smaller stomach, so you feel full on less.
Gastric bypass
A smaller stomach and a new route for food.
MagDI™New
The bypass made with magnets instead of staples. Only at Auralia.
What the operation does
- Sleeve
- Around 80% of the stomach is removed, leaving a slim sleeve. You feel full on smaller portions.A smaller stomach
- Bypass
- A small stomach pouch is made and part of the intestine is rerouted, joined with staples in two places.Small pouch and a new route for food
- MagDI™
- Two small magnets join two parts of the small intestine, so food takes a shorter route. The bowel is not divided.A new route for food, made by magnets
Is the bowel cut or stapled?
- Sleeve
- No. The staples are on the stomach only.No. Staples on the stomach only
- Bypass
- Yes, at two connections.Yes, in two places
- MagDI™
- No cutting or stapling at the connection. Your body forms it within 2 to 3 weeks.Not at the connection
Effect on hunger and fullness hormonesThe hormonal effect is a big part of why weight stays off.
- Sleeve
- Moderate
- Bypass
- Strong
- MagDI™
- Strong
Effect on type 2 diabetes
- Sleeve
- Good
- Bypass
- Strong
- MagDI™
- Promising in the first published study. Longer-term data is still being gathered.Promising early results
Hospital stay and recovery
- Sleeve
- Usually 1 night in hospital. Around 2 weeks recovery on average.Usually 1 night. About 2 weeks recovery
- Bypass
- Usually 1 night, sometimes 2. Around 2 weeks recovery on average.1 night, sometimes 2. About 2 weeks recovery
- MagDI™
- A short stay, which Dr Loy confirms at your assessment. Most people are back at desk work within 1 to 2 weeks.A short stay. Desk work in 1 to 2 weeks
What stays inside
- Sleeve
- The staple line on the stomachThe staple line
- Bypass
- The staples at the two connectionsThe staples
- MagDI™
- The magnets pass naturally, around six weeks after surgery.Magnets pass in around six weeks
How long it has been used
- Sleeve
- DecadesDecades
- Bypass
- DecadesDecades
- MagDI™
- New to Ireland, not new to medicine. In use since 2021 and offered in around 40 centres in the United States.Since 2021. New to Ireland, not new to medicine
A general guide, not a promise. Your own plan depends on your health and history.
Which Might Suit You?
How surgeons usually think about each option. A starting point, not a diagnosis.
Gastric bypass
Often considered where reflux or type 2 diabetes is part of the picture, or where there is more weight to lose.
MagDI™
Worth asking about if a bypass appeals, but you would rather the bowel was not cut or stapled at the connection. It is new, and not suitable for everyone.
The surgeon decides with you.
Dr Loy recommends the option that fits your health, history and goals. If that is a different procedure, or no surgery at all, he will tell you.
What Happens Next
- 1
A patient coordinator calls you
Within one working day, to answer your first questions.
- 2
Your free assessment with Dr Loy
In person in Dublin or online from home. He looks at all three options with you.
- 3
A written plan and one price
All-inclusive, with monthly payments if you want them. No obligation.
See which option suits you
Leave your details. Your free assessment with Dr Loy is where you find out which option fits you.
Thank you.
On the live page, a patient coordinator would now call you within one working day to arrange your free assessment with Dr Loy.
Preview only: nothing was sent
One Surgeon. All Three Options.
Dr John Loy, Consultant Bariatric and Metabolic Surgeon, Head of Bariatric Surgery at Auralia
Dr Loy performs the gastric sleeve, the gastric bypass and MagDI™, and he is the first surgeon in Ireland certified for MagDI™. With almost 3,000 weight loss procedures behind him, his advice starts from what fits you, so his advice starts from what fits you. You meet him at your first consultation, he performs your surgery, and he sees you at your follow-ups.
Almost 3,000weight loss procedures
First in Irelandsurgeon certified for MagDI™
Headof Bariatric Surgery at Auralia
Meeting Dr Loy to discuss the best surgery for me, I felt it was the first time in my life I was genuinely being listened to and not just blamed or judged for being overweight.
Sarah K., gastric sleeve patient, Trustpilot, April 2026
Care That Stays In Ireland
Whichever option you choose, the care around it is the same, and it stays close to home.
Aftercare that stays in Ireland
Your surgeon, your dietitian, the Auralia app and a 24/7 surgical emergency line for the first year. At 2am, you call us.
No long waiting list
A free consultation with Dr Loy, in person in Dublin or online from home, without a long wait.
An accredited Irish hospital
Surgery at Auralia Private Hospital, Dublin, Ireland's first internationally accredited private hospital.
4.8
4.7
His compassion and professionalism gave me confidence in one of the most important decisions of my life.
Miroslav P., gastric sleeve patient of Dr Loy, Trustpilot, November 2025
25 years caring for patients in Ireland40,000+ patientsDublin or online consultations
What Each Option Costs
One all-inclusive price, paid monthly over 36 months. No hidden fees.
Sleeve
from
€297
a month
Bypass
from
€337
a month
MagDI™
from
€359
a month
MagDI™ figure is for MagDI™ on its own. Your written quote reflects the plan Dr Loy recommends.
Included with every option
Surgeon's fee and pre-operative tests
Hospital, anaesthesia and your stay
Dietitian support and the Auralia weight loss app
Follow-ups, surgical insurance and Irish aftercare
You get your written plan and full price before you decide anything.
Your Questions, Answered
Neither is better for everyone. The sleeve is often a first choice for people who want to feel full on smaller portions. The bypass is often considered where reflux or type 2 diabetes is part of the picture. MagDI™ is a new way to get a bypass effect without cutting or stapling the bowel at the connection.
The right one depends on your health, your history and your goals. That is exactly what the free assessment with Dr Loy is for.
No. Your free consultation covers MagDI™, the gastric sleeve, the gastric bypass, the Allurion balloon and non-surgical options, and Dr Loy recommends the one that fits your health and goals.
It belongs to the same family. Like a bypass, MagDI™ creates a new connection in the small intestine, so food and digestive juices meet further along the gut. This changes the hormones that control hunger and blood sugar.
The difference is how the connection is made: with two small magnets and your own healing, instead of cutting the bowel and joining it with staples. The bowel is not divided. Dr Loy will recommend the right approach for you.
It is new to Ireland, not new to medicine. MagDI™ has been in clinical use since 2021, is authorised by the US FDA and Health Canada, and is CE marked in Europe. In the published studies the magnets have connected successfully in every patient, and no leak has been reported at the magnetic connection.
As with any surgery there are risks, including bleeding, infection, hernia and, rarely, the need for a further procedure. Because it is new, long-term data beyond two years is still being collected. It is not suitable if an MRI scan is planned in the weeks after surgery. Dr Loy will go through all of this with you.
No. The new connection forms within 2 to 3 weeks, and the magnets then pass naturally, usually around six weeks after surgery. Most people do not notice. A simple X-ray confirms they have gone.
MagDI™ needs specific training and supervised cases before a surgeon is certified. Dr Loy is the first surgeon in Ireland certified to perform it, and Auralia Private Hospital is the only Irish hospital offering it.
Still deciding? That is what the free assessment is for.
A patient coordinator calls you within one working day to arrange your free assessment with Dr Loy. No obligation.