Gastric sleeve in Türkiye: the procedure, the risks and aftercare at home

Gastric sleeve surgery is one of the most common operations for severe obesity in the UK – and one of the procedures for which the most people travel to Türkiye. The reasons are obvious: NHS waiting lists are long, the criteria are strict, and private surgery at home costs considerably more than in Antalya.

This guide explains plainly what the operation does, who qualifies, what the risks are, how the stay works and – the most important point – how aftercare at home must be organised. It is not a substitute for medical advice.

What happens during gastric sleeve surgery

In a gastric sleeve (sleeve gastrectomy), the surgeon removes about 80 per cent of the stomach. What remains is a narrow tube that only holds small amounts. The operation is done by keyhole surgery through several small incisions and usually takes one to two hours under general anaesthetic.

It works through two mechanisms:

• Less room: you can only eat small portions and feel full quickly.
• Less hunger: the removed part of the stomach contains most of the cells that produce the hunger hormone ghrelin. Many patients report that constant hunger fades.

The small intestine is left unchanged – unlike in a gastric bypass. That makes the operation technically simpler and nutrients are absorbed somewhat better. The operation cannot be reversed.

Who qualifies

Obesity surgery is not a cosmetic procedure but a treatment for a chronic disease. The decision should be based on a thorough assessment – not on a WhatsApp photo.

International guidelines

The American and international societies for bariatric surgery (ASMBS and IFSO) updated their recommendations in 2022:

BMI	Recommendation
over 35	surgery can be considered – regardless of other conditions
30 to 35	surgery may be recommended with type 2 diabetes or where lasting weight loss cannot be achieved otherwise

Lower thresholds apply to people of Asian origin, because related diseases develop earlier.

The situation in the UK

NHS criteria are stricter. For NHS-funded surgery you generally need a BMI of 40 or more, or 35 or more with a serious condition such as type 2 diabetes, plus evidence that you have tried and not succeeded with a structured weight management programme. The route runs through specialist weight management services and often takes a year or longer. Many patients therefore opt for self-funded surgery – in the UK or abroad.

Who should not be operated on

Reasons against surgery include untreated eating disorders, active addiction, severe untreated mental illness and certain digestive conditions. If you already have significant reflux or a hiatus hernia, a sleeve is often not the best choice – a gastric bypass is usually preferred. A reputable clinic checks this before surgery and will also turn patients away.

What you can realistically expect

On average, patients lose 60 to 70 per cent of their excess weight after a gastric sleeve within one to two years. Someone who is 1.70 m tall and weighs 130 kg has around 60 kg of excess weight compared with a normal weight of about 70 kg – a typical result would be 35 to 45 kg less.

Related conditions often improve markedly: type 2 diabetes, high blood pressure, sleep apnoea and joint problems. That is the real medical benefit.

But: the operation is a tool, not a solution. Some weight can come back after years if eating habits do not change permanently. And the operation does not change why someone eats – with emotional eating, psychological support is needed as well.

Risks and complications

Gastric sleeve surgery is now a routine procedure with low mortality (on average below 0.2 per cent). Nevertheless, there are risks you should know about:

In the first days and weeks

• Staple line leak: the most feared complication. Stomach contents escape into the abdomen and a serious infection can develop. It occurs in roughly one in a hundred patients, usually in the first two weeks – often after you have already returned home. Warning signs: a racing heart, worsening abdominal pain, pain in the left shoulder, fever.
• Bleeding: usually in the first hours to days.
• Blood clots and pulmonary embolism: obesity is a risk factor in itself. Clot prevention with injections is often prescribed for several weeks.
• Dehydration: after surgery it is hard to drink enough. Dehydration is a common reason for readmission to hospital.

Long term

• Acid reflux: the most common long-term consequence. Studies report that up to half of patients develop reflux symptoms long term or find existing symptoms get worse. Acid-suppressing medication often helps; with severe reflux, conversion to a gastric bypass may be necessary.
• Narrowing of the sleeve (stenosis): difficulty swallowing and vomiting; usually widened endoscopically.
• Nutrient deficiencies: vitamin B12, vitamin D, iron, folic acid, calcium – hence the lifelong supplements.
• Gallstones: due to rapid weight loss.
• Hair loss: common in the first months, usually temporary.
• Excess skin: often a burden after major weight loss; skin removal surgery is rarely funded by the NHS.
• Alcohol: after obesity surgery the risk of problem drinking is increased – partly because alcohol acts faster and more strongly.

Which warning signs after your return require an immediate visit to a doctor is explained in our guide Warning signs after surgery.

How treatment in Antalya typically works

Before you travel

• Online consultation with photos, weight, existing conditions and medication list
• Quote and contract – what to look out for is explained in our guide Your treatment contract with a Turkish clinic
• Many clinics require a pre-operative diet of one to two weeks to shrink the liver and make the operation safer – stick to it

On site

Day	What happens
Day 0	Arrival, transfer to hotel or straight to the clinic
Day 1	Pre-operative assessment: blood tests, ECG, ultrasound, often an endoscopy; consultation with surgeon and anaesthetist; information and consent
Day 2	Operation, monitoring
Days 3–4	First sips of water, getting mobile, check of the staple line (e.g. contrast X-ray), discharge to hotel
Days 5–7	Liquid diet, follow-up check, discussion of diet plan and medication
Days 7–8	Flight home, if the surgeon agrees

The exact schedule varies from clinic to clinic. Be suspicious if the pre-operative assessment is cut to a minimum, if you are discharged the day after surgery, or if your flight home is fixed for day 4 or 5.

Questions to ask the clinic

1. Is the clinic authorised for international health tourism?
2. Who will operate on me, and how many gastric sleeve operations does he or she perform per year?
3. Which pre-operative tests are done – including an endoscopy?
4. How is the staple line checked after surgery?
5. What happens in the event of a leak – is there an intensive care unit and experience with endoscopic treatment?
6. For how long will I receive clot prevention?
7. What diet plan and vitamin recommendations will I be given in writing?
8. Who is my contact after I return home, and are video check-ups offered?
9. Is there complication insurance, and what does it cover?

More in our checklist for choosing a clinic.

Eating after the operation

Food is reintroduced in stages – your clinic sets the exact timings:

1. Liquids (about weeks 1–2): water, unsweetened tea, clear broth, later protein drinks. In small sips, spread over the day.
2. Puréed (about weeks 3–4): yoghurt, puréed soups, cottage cheese, soft egg.
3. Soft (about weeks 5–6): steamed vegetables, fish, tender meat.
4. Normal (from about week 7): solid food in small portions.

Permanent rules:

• Protein first: 60 to 80 grams of protein a day is the goal, to avoid losing muscle.
• Eat slowly, chew thoroughly, small bites.
• Do not eat and drink at the same time – leave about 30 minutes between them.
• No fizzy drinks, no sugary drinks.
• At least 1.5 litres of fluid over the day.

In detail – with a protein table, an example day and help with common problems: Eating after gastric sleeve surgery.

Aftercare at home – the decisive point

This is the biggest difference between surgery through the NHS and surgery in Türkiye. After NHS surgery you are attached to a bariatric service that monitors blood results, adjusts vitamins and steps in when there are problems. After surgery in Antalya you have to organise this structure yourself – before you travel.

What UK guidance recommends

The British Obesity and Metabolic Surgery Society (BOMSS) recommends lifelong supplementation after a gastric sleeve, typically:

• A complete multivitamin and mineral supplement, daily
• Vitamin B12, usually as an injection every three months or as a daily oral supplement
• Vitamin D and calcium, daily
• Iron where needed, especially for women before the menopause

Monitoring: blood tests at about 3, 6 and 12 months after surgery, then once a year – including full blood count, kidney and liver function, ferritin, folate, vitamin B12, vitamin D, calcium and, in people with diabetes, HbA1c. Clinical reviews are usually scheduled at similar intervals in the first two years.

How to organise your aftercare

1. Involve your GP – before you travel. Explain what is planned and ask whether the practice will take on the blood tests and monitoring. GPs can follow the BOMSS guidance for shared care.
2. Ask about bariatric follow-up. Some NHS or private bariatric services take on patients operated on elsewhere, others do not. Ask specifically.
3. Secure dietetic support. A registered dietitian with bariatric experience is very valuable in the first months.
4. Have your medication adjusted. Diabetes and blood pressure medication often needs reducing after surgery – a doctor must oversee this.
5. Bring your documents: surgical report in English, details of the procedure, diet plan, medication list.
6. Consider psychological support, especially if food has had an emotional role.
7. Find a support group. Talking to others who have had surgery helps many people through the first year.

Who pays for what

You pay for the operation abroad yourself. Emergency and medically necessary treatment of complications is provided by the NHS. Routine blood tests through your GP are NHS services; vitamin supplements you usually pay for yourself. Structured bariatric follow-up may have to be arranged privately. More on this: Complications after cosmetic surgery abroad: will the NHS help?

Gastric sleeve or gastric bypass?

	Gastric sleeve	Gastric bypass
Principle	stomach is reduced	stomach reduced and small intestine rerouted
Operating time	shorter	longer
Weight loss	high	somewhat higher
Reflux	can develop or get worse	usually improves
Nutrient deficiencies	moderate	greater, more supplements
Dumping syndrome	rare	more common
Reversible	no	in principle, but complex
Suitable with reflux / hiatus hernia	generally not	yes

Which procedure suits you should be decided with the surgeon after assessment – including an endoscopy. A clinic that offers every patient the same procedure is not a good sign.

Flying and travelling after surgery

Obesity and abdominal surgery increase the risk of blood clots. Plan at least a week on site, wear compression stockings, take the clot-prevention injections as prescribed and drink small sips regularly on the plane. More in Flying after surgery: when is it safe?

Read more

• Warning signs after surgery: when to see a doctor straight away
• How to choose a reputable clinic in Türkiye
• Your treatment contract with a Turkish clinic: what to check