A gastric sleeve removes a large part of the stomach. A gastric bypass makes a small stomach pouch and reroutes part of the small intestine. Both are established operations that differ on reversibility, reflux and vitamin needs. Your surgeon recommends one after assessment.
How does a gastric sleeve work?
A sleeve gastrectomy removes a large part of the stomach and leaves a narrow, tube-shaped one. You feel full on smaller meals, and some hunger-related hormones change too. Nothing is rerouted, so food follows its usual path.
It is usually done by keyhole surgery. Because part of the stomach is taken out, a sleeve cannot be reversed. There is more on our gastric sleeve in Antalya page.
How does a gastric bypass work?
A Roux-en-Y gastric bypass makes a small pouch at the top of the stomach and joins it straight to a lower part of the small intestine. Food skips most of the stomach and the first section of intestine. Portions are limited, and the body absorbs some nutrients differently.
A mini gastric bypass (one anastomosis gastric bypass) uses a longer, narrower pouch with a single connection to the small intestine. See gastric bypass in Antalya and mini gastric bypass in Antalya.
The main differences at a glance
It comes down to four things: whether the intestine is rerouted, whether the operation can be reversed, what it may do to reflux, and how closely your vitamins need watching.
| Gastric sleeve | Roux-en-Y gastric bypass | Mini gastric bypass | |
| How it works | Removes a large part of the stomach; no intestinal rerouting | Small stomach pouch connected to the small intestine | Longer pouch with a single connection to the small intestine |
| Reversibility | Not reversible | Reversal possible in principle, but complex and rarely done | Reversal possible in principle, but complex |
| Reflux considerations | May cause or worsen reflux in some people | Often considered for people with significant reflux | Bile reflux is a recognised consideration |
| Vitamin supplementation | Lifelong supplements and regular blood tests | Lifelong supplements; closer monitoring usually needed | Lifelong supplements; closer monitoring usually needed |
| Hospital nights (MYK package) | 2 | 2–3 | 2–3 |
Every MYK Healthroutes bariatric package also includes 7 hotel nights, VIP airport transfers and 2-year aftercare.
Which operation is better for reflux?
If you already have significant acid reflux, surgeons often lean towards a Roux-en-Y gastric bypass, because a sleeve can cause new reflux or make existing reflux worse in some people. It is not a fixed rule. Your symptoms, any test results and your wider health all count.
Mention any heartburn, indigestion or reflux medication at pre-assessment, however minor.
Do you need vitamins after both operations?
Yes. With either operation you take vitamin and mineral supplements for life and have regular blood tests. A bypass changes how nutrients are absorbed, so monitoring is often closer, especially for iron, vitamin B12, calcium and vitamin D.
You will get a supplement plan before you leave, and your GP can help with blood tests in the UK. Deficiencies creep up slowly if you skip supplements, so make them part of your daily routine.
How do recovery and hospital stay compare?
Recovery follows a similar pattern for both: a short hospital stay, then a staged diet that moves from liquids to purées to soft food over several weeks. In our packages a sleeve includes 2 nights in hospital and a bypass or mini bypass 2–3 nights, each followed by 7 hotel nights.
While you are at the hotel, the team checks on you and confirms when you can fly. Most people are back at desk work after a few weeks, but that depends on your recovery and your job.
How do you decide which operation is right for you?
You decide together with your surgeon after a full assessment. They look at your BMI, conditions such as type 2 diabetes or reflux, previous operations, medication and what you would prefer. Neither operation suits everyone, and all surgery carries risks.
Things to ask your surgeon:
- Why are you recommending this operation for me?
- How might it affect any reflux I have?
- What supplements and blood tests will I need, and for how long?
- What are the main risks in my case?
- What happens if I need further treatment later?
How MYK Healthroutes can help
MYK Healthroutes is a licensed health tourism agency in Antalya, Türkiye, coordinating bariatric, plastic, dental, hair and dermatology treatment for international patients. Independent, licensed doctors operate at our partner hospitals; we send your medical information to the bariatric surgeon, arrange tests, hospital, hotel and transfers, and stay in touch for 2 years after you go home. Read our overview of bariatric surgery in Türkiye or Message us on WhatsApp.
Frequently asked questions
Can I choose between a sleeve and a bypass myself?
Your preference matters and you should say it. The surgeon makes the final recommendation once they have assessed your health and history.
Is a gastric bypass reversible?
In principle, yes, but reversal is a complex operation and rarely done. A gastric sleeve cannot be reversed.
Can a gastric sleeve be converted to a bypass later?
Sometimes. Revision surgery may be considered, for example for severe reflux, and the surgeon looks at each case individually.
How long is the hospital stay for each operation?
In MYK Healthroutes packages, a sleeve includes 2 hospital nights and a bypass or mini bypass 2–3 nights, plus 7 hotel nights.