
Illustration · Stomach and waistBeforeAfter2026 prices, how it differs from a sleeve, and life afterwards
A Roux-en-Y gastric bypass creates a small stomach pouch and reroutes the small intestine, so you eat less and absorb fewer calories. At Valentmedica, an all-inclusive package in Istanbul costs £3,400–£4,300, with a bariatric surgeon, three nights in a JCI-accredited hospital and a dietitian who stays with you for a year.
Patients who travelled to Istanbul with Valentmedica, photographed at 12 and 24 months. Starting BMI and total loss are listed with each case, because the honest answer to "how much will I lose" depends entirely on where you start.
A Roux-en-Y gastric bypass divides the stomach into a small upper pouch and a much larger remnant, then connects that pouch directly to the middle of the small intestine — so food bypasses most of the stomach and the first section of bowel.
The operation is done through four or five keyhole incisions under general anaesthetic and takes two to three hours. The new pouch holds about 30 ml, roughly the size of an egg. The small intestine is divided and the lower end is brought up and joined to the pouch; the upper end, carrying stomach acid and digestive enzymes, is reconnected further down. The result is a Y shape, which is where the name comes from.
Three mechanisms drive the weight loss, and this is why the bypass remains the benchmark operation. The pouch restricts how much you can eat. Bypassing the first part of the intestine reduces how many calories you absorb. And rerouting food past the duodenum changes gut hormone signalling in a way that affects appetite and blood sugar directly — which is why type 2 diabetes often improves within days, long before meaningful weight is lost.
| Gastric bypass | Gastric sleeve | |
|---|---|---|
| Excess weight loss | 65–80% | 60–70% |
| Type 2 diabetes remission | Higher | Good |
| Effect on acid reflux | Usually improves it | Can make it worse |
| Vitamin absorption | Significantly reduced | Less affected |
| Technically reversible | Yes, rarely done | No |
| Operating time | 2–3 hours | 1–2 hours |
The short version: a bypass gives slightly more weight loss, is better for severe reflux and stronger for diabetes, but demands more rigorous lifelong supplementation and carries a slightly higher complication rate. A sleeve is simpler and gentler on nutrition. Our detailed guide to gastric sleeve versus gastric bypass sets out the trade-offs case by case.
A Valentmedica all-inclusive gastric bypass package in Istanbul costs £3,400–£4,300. The same operation privately in the UK is typically £12,000–£16,000, and in the United States $20,000–$30,000.
| Procedure | Price (GBP) | Hospital nights | Nights in Turkey |
|---|---|---|---|
| Gastric bypass (Roux-en-Y) | £3,400–£4,300 | 3 | 7 |
| Mini gastric bypass | £3,200–£4,000 | 3 | 7 |
| Gastric sleeve | £2,900–£3,800 | 3 | 7 |
| Revision: sleeve to bypass | £4,200–£5,400 | 3–4 | 8 |
| Revision: band to bypass | £4,400–£5,600 | 3–4 | 8 |
Flights are excluded so you can choose your own route and fare. Also excluded: travel insurance that covers bariatric surgery abroad, meals beyond hotel breakfast, your ongoing vitamin supply after the starter pack, and treatment for any pre-existing condition found during your work-up. There are no consultation fees at any stage.
Elsewhere you usually pay for the operation alone. A Valentmedica package also includes your hospital stay, hotel, transfers and a personal coordinator.
Prices are indicative ranges in pounds. France, Italy and Spain: estimated from private prices in Germany.
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Indicative figures, not a quote. Bars show the usual range in each market; overseas figures are typically surgeon and facility only. Flights are an estimate for a return economy fare. Your price is confirmed in writing after a clinician has reviewed your case.
The usual criteria are a BMI of 40 or above, or 35 or above with a weight-related condition. A bypass is particularly favoured where there is severe acid reflux or type 2 diabetes.
Our BMI and eligibility calculator shows where you sit against the standard criteria in about a minute, and a bariatric surgeon reviews your details free of charge before you commit to anything.
Seven nights in Istanbul: three in hospital and four in the hotel, covering the window in which complications appear.
You complete a medical questionnaire and send recent blood results. A bariatric surgeon and a dietitian review them and confirm whether a bypass or a sleeve suits you better. You receive a written fixed quote and start the two-week liver-shrinking diet at home.
Your driver meets you at Istanbul airport and takes you to the hotel. Rest after the flight.
Blood tests, ECG, chest X-ray, abdominal ultrasound and an endoscopy, then consultations with your surgeon, the anaesthetist and the dietitian. You are admitted in the evening.
The operation takes two to three hours. You wake in your room and will be asked to stand and walk the same evening, which is what prevents blood clots.
A swallow test confirms both joins are sealed, after which you begin sips of water and clear liquids.
You move to the hotel, walking regularly, with your coordinator checking in daily.
Light activity only. Your coordinator is on WhatsApp at any hour and the hospital is fifteen minutes away.
Bloods repeated, your surgeon confirms you are fit to fly, and you leave with your discharge summary, medication, supplements and a written diet plan.
Dietitian appointments at 2 weeks, 1, 3, 6 and 12 months, with your surgeon available throughout.
The hospital and hotel you will be using, and the specifics you can check before you pay a deposit.
The facility is named to you in writing, with its licence and accreditation numbers, so you can verify it rather than take our word for it. If you would like to see the building, ask: we can usually arrange a visit before you decide.
Keyhole surgery under general anaesthetic, taking two to three hours, through four or five small incisions in the abdomen.
Expect three to four weeks before you are back at a desk, six weeks before heavy activity, and about six weeks of staged diet before you return to normal-texture food in much smaller amounts.
A gastric bypass is major abdominal surgery with two surgical joins. In experienced hands mortality is around 0.3%, but it carries a slightly higher complication rate than a sleeve and demands lifelong follow-up.
Valentmedica works only with JCI-accredited private hospitals in Istanbul that run a dedicated bariatric programme with intensive care on site, and with surgeons registered with the Turkish Ministry of Health who perform this operation routinely. You are given your surgeon's name and registration number before you pay anything.
Tell your GP before you travel. A discharge summary in English and a GP who knows what was done makes aftercare at home far easier, and Valentmedica provides the paperwork as standard.
A hiatus hernia repair or gallbladder removal can be done in the same operation where clinically justified. Cosmetic body contouring is a separate trip, 12 to 18 months later.
Your surgeon will only add a second procedure where there is a clinical reason, because longer operating times in bariatric surgery raise the risk of clots and wound problems in patients already at higher risk.
Do not book body contouring alongside your bypass. Operating before your weight has stabilised produces a result that will not hold, and combining two major operations is not safe.
Follow the two-week liver-shrinking diet, stop smoking, arrange your blood tests, organise help at home for the first few weeks, and get your GP involved before you travel.
Most patients lose 65–80% of their excess weight within 12 to 18 months. The weight comes off fastest in the first six months, and what happens after year two depends on habits far more than on the operation.
A realistic picture: someone starting at 135 kg with an ideal weight around 70 kg has 65 kg of excess weight, and would typically expect to lose 42–52 kg. Most of that happens in the first six to nine months. A regain of 5–10% between years two and five is common and is the normal shape of the curve rather than a failure.
The patients who hold the result are the ones who kept attending follow-up and never stopped the supplements. Protein at every meal, separating drinking from eating, lifelong vitamins and annual bloods are what sustain it. Valentmedica includes twelve months of structured dietitian support for exactly this reason, and you can see outcomes at 12 and 24 months in our weight-loss before and after gallery.
At Valentmedica, £3,400–£4,300 as an all-inclusive package. That covers the bariatric surgeon, anaesthetist, three nights in a JCI-accredited hospital, all pre-operative tests including endoscopy, four hotel nights, transfers and twelve months of dietitian follow-up. Flights are not included.
Seven nights. Three in hospital and four in the hotel, so you are still in Istanbul during the window when a leak at either join would typically appear.
A bypass gives slightly more weight loss, is considerably better if you have severe acid reflux, and has the highest remission rate for type 2 diabetes. A sleeve is a simpler operation and affects vitamin absorption far less. Severe reflux points strongly to a bypass; a reluctance to commit to lifelong supplements points to a sleeve.
Most patients lose 65–80% of their excess weight within 12 to 18 months — not of their total body weight. If you weigh 135 kg with an ideal weight of 70 kg, expect to lose roughly 42–52 kg.
Technically yes, unlike a sleeve, because no stomach is removed. In practice reversal is rare, complex and only done for serious complications. Treat it as permanent.
Yes, without exception. A bariatric multivitamin, B12, iron, calcium and vitamin D are standard, with annual blood tests. Bypassing the duodenum permanently reduces absorption, and untreated deficiencies can cause irreversible nerve damage.
When sugary or very fatty food passes quickly into the small intestine, it draws in fluid and triggers cramping, nausea, sweating, a racing heart and diarrhoea, usually within 30 minutes. It affects a large proportion of bypass patients. Most find it an effective deterrent and learn their triggers within a few months.
Paracetamol yes; anti-inflammatories no. Ibuprofen, naproxen, diclofenac and aspirin substantially raise the risk of a marginal ulcer at the join, which can perforate. This restriction is permanent — tell every doctor and dentist you see.
Very often, and quickly. Many patients need far less medication within days, before meaningful weight loss, because of the hormonal effect of rerouting food past the duodenum. This must be managed by your doctor — do not adjust insulin yourself.
Yes, and fertility often improves. Surgeons advise waiting at least 12 to 18 months until your weight is stable and nutrition is good, using reliable contraception meanwhile. Pregnancy after a bypass needs closer monitoring of vitamin levels than usual.
Most patients who lose a large amount of weight have some, particularly on the abdomen, arms and thighs. Body contouring is possible once your weight has been stable for six months, usually 12 to 18 months after the bypass.
Contact your coordinator at any hour. You go home with a full discharge summary in English for your GP, and Valentmedica liaises with your surgeon directly. Persistent cramping abdominal pain months or years later should always be investigated urgently for an internal hernia — make sure your local doctors know you have had a bypass.
Short, unscripted videos from patients who travelled with us, including gastric bypass.
Answer 7 quick questions to see if a gastric bypass could be right for you. No personal details needed to see your result.
Answer honestly; there are no wrong answers. You will see your result straight away.
Based on your answers, a gastric bypass may be a good option for you. The next step is a free online assessment with our bariatric team.
A gastric bypass could still be right for you, but a few points should be reviewed by a surgeon first — a sleeve may also be worth discussing.
Based on your answers, it may be better to address a few things first. Our team is happy to talk through your options, with no obligation.
This self-check is for guidance only and is not a medical diagnosis. Your surgeon will confirm your suitability.