Concierge bariatric surgery · UK
Laparoscopic mini-gastric bypass, by a BOMSS-registered bariatric surgeon.
A one-anastomosis gastric bypass (MGB/OAGB) — technically simpler than Roux-en-Y, often greater weight loss, strong type 2 diabetes remission. With the MDT, the liver-shrinkage diet and the lifelong follow-up done properly.
Why patients choose us
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A BOMSS-registered bariatric surgeon
Not a general surgeon dabbling in weight-loss work. A named bariatric consultant on the BOMSS register, in a high-volume unit.
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MGB or RYGB — the honest comparison
MGB is simpler and often gives greater weight loss. RYGB has longer-term data and less bile reflux. We set both out before you choose.
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Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Indicative pricing
What a private mini-gastric bypass costs in the UK.
Indicative ranges across our partner units. Send the details and we quote firm figures across two or three surgeons.
In short
A laparoscopic MGB in our UK network: £11,000–£16,000, home after 1–2 nights.
| Procedure | Indicative range | Typical duration | Recovery |
|---|---|---|---|
| Laparoscopic mini-gastric bypass (self-pay) | £11,000–£16,000 | 60–90 min | 1–2 night stay |
| Robotic mini-gastric bypass | £13,000–£18,000 | 90–120 min | 1–2 night stay |
| Revision surgery (sleeve or band to MGB) | £14,000–£20,000 | 120–180 min | 2–3 night stay |
| Pre-op MDT work-up (dietician + psychology) | £800–£1,500 | 2–4 weeks | Included in most packages |
| Upper GI endoscopy (pre-op) | £1,200–£2,000 | 30 min | Same visit |
| Consultation only | £250–£450 | 45 min | Same visit |
Prices vary by unit, by which bariatric surgeon leads the case, by whether the operation is laparoscopic or robotic, and by whether it is a first-time or revision procedure. NHS-funded pathways exist for eligible patients under NICE NG246.
The problem
The right operation, chosen properly — not the surgeon’s default.
Which bariatric operation you have matters more than most patients are told. MGB, RYGB, sleeve and duodenal switch are all different trade-offs. We help you make the choice, not have it made for you.
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Sleeve or bypass?
A sleeve is simpler but has more reflux and slightly less weight loss. A bypass gives greater and more durable results — but at a higher nutritional cost.
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MGB or RYGB?
MGB is technically simpler with often greater weight loss; RYGB has longer-term data and less bile reflux. We set both trade-offs out honestly.
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Ready for lifelong care?
Bariatric surgery is not an event — it is a lifelong relationship with a dietician, a set of vitamins and annual bloods. We only recommend it when you are.
The journey
From enquiry to lifelong follow-up — what happens, in order.
One MDT from the first assessment to the annual review — with a plan you can actually stick to.
Phase 1 · Before your procedure
MDT work-up and liver-shrinkage diet
Phase 2 · On the day
One or two nights in hospital
Phase 3 · After
Lifelong follow-up
- 01
Before
You tell us what is going on
A short, confidential form. Weight, BMI, comorbidities, previous diets, whether GLP-1 medication has been tried.
- 02
Before
MDT assessment and Tier 3 work-up
Bariatric surgeon, dietician, psychologist and endocrinology. Bloods, endoscopy, sleep study if snoring, cardiology if needed.
- 03
Before
Liver-shrinkage diet, 2–4 weeks
A very low-energy diet (Slimfast or Optifast) shrinks the liver and makes the laparoscopic view safe. Stop smoking six weeks ahead; stop NSAIDs.
- 04
On the day
Admission and theatre
Admission, consent and a chat with the surgeon and anaesthetist. General anaesthetic, VTE prophylaxis and antibiotics on induction.
- 05
On the day
The procedure itself
60–90 minutes laparoscopically. A long tubular gastric pouch is stapled along the lesser curve and joined to a jejunal loop 150–200 cm from the ligament of Treitz. Leak test.
- 06
On the day
ERAS recovery on the ward
No nasogastric tube, sips of water within hours, mobilised the same evening. Home after one or two nights.
- 07
After
Lifelong follow-up and vitamins
Liquid → puree → soft → solid over six weeks. Lifelong multivitamin, iron, B12, calcium and vitamin D. Dietician and surgeon reviews at 6 weeks, 3, 6, 12 months, then annually.
Typical end-to-end: 6–8 weeks from enquiry to theatre. Full staged diet: 6 weeks. Follow-up: for life.
When it helps
When a mini-gastric bypass is the right operation.
The NICE NG246 indications, the factors that favour MGB over RYGB, and the one situation where a standard Roux-en-Y is the safer choice.
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BMI 40 or higher
The primary NICE (NG246) indication for bariatric surgery in adults, after Tier 3 non-surgical management has been tried.
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BMI 35 with obesity-related disease
Type 2 diabetes, hypertension, obstructive sleep apnoea, non-alcoholic fatty liver or severe joint disease.
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BMI 30 with new-onset type 2 diabetes
NICE now supports assessment for surgery at BMI 30 or above in recent-onset T2DM, particularly where remission is a goal.
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Failed Tier 3 non-surgical management
Behavioural change, dietician input, medical therapy and a trial of a GLP-1 receptor agonist have not produced sustained weight loss.
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T2DM primary indication
MGB has some of the strongest T2DM remission data of any bariatric procedure — worth discussing when diabetes drives the decision.
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Previous abdominal surgery
A single anastomosis and no Roux limb make MGB technically simpler than RYGB after adhesions from previous surgery.
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Very high BMI (over 50)
The shorter operative time of MGB can be an advantage in the highest-risk patients.
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When RYGB is better
Severe pre-existing GORD, Barrett’s oesophagus or a strong family history of gastric cancer — MGB’s bile-reflux risk makes standard Roux-en-Y the safer choice.
Procedure options
MGB is one of four bariatric operations to weigh up.
What each option actually involves — and which trade-offs fit which patient.
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Mini-gastric bypass (MGB/OAGB)
A long gastric pouch and a single loop anastomosis 150–200 cm downstream. Simpler than RYGB, often greater weight loss, more bile-reflux risk.
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Roux-en-Y gastric bypass (RYGB)
A small pouch with two anastomoses (Roux limb). The long-established comparator. Less bile reflux, more internal-hernia risk. See our RYGB page.
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Sleeve gastrectomy
Removes 70–80% of the stomach as a tube. No anastomosis. Simpler still, less malabsorption, but more reflux and slightly less weight loss than MGB.
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Duodenal switch (BPD/DS)
A sleeve plus a very short common channel — the most powerful weight-loss operation, and the most nutritionally demanding.
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Robotic mini-gastric bypass
The same operation with a robotic platform — increasingly offered in UK private units for revision cases and very high BMI.
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Revision to MGB
From a failed band or sleeve. Technically demanding but a common indication for MGB’s single-anastomosis simplicity.
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Conversion MGB → RYGB
If bile reflux becomes significant, MGB can be converted to a standard Roux-en-Y. Rare, but a reason MGB is described as reversible.
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Consultation only
An honest discussion about whether surgery is right, which operation fits, and how the lifelong commitment looks — no obligation.
Our vetted UK network
A small panel of bariatric MDTs, we picked them.
BOMSS-registered bariatric surgeons across London, the South East, the Midlands and the North West. Not listed publicly — introductions are made privately, once we understand your case.
Selection criteria
How we choose every bariatric MDT in our network.
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Bariatric consultants on the BOMSS register, in high-volume UK units
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Full MDT: bariatric surgeon, dietician, psychologist, endocrinology
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MGB and RYGB both offered — the choice is yours, not the surgeon’s preference
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Structured lifelong follow-up with blood monitoring for nutritional deficiency
Safety and recovery
What to expect afterwards — honestly.
MGB is a safe operation in high-volume hands, but it is major surgery with lifelong consequences. The risks worth understanding: bile reflux, marginal ulcer, nutritional deficiency, and the pregnancy window.
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Anastomotic leak, 1–2%
The single anastomosis is tested in theatre with methylene blue or endoscopy. Leaks usually declare within 72 hours and are managed promptly.
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Bleeding and VTE
Bleeding 1–3% and venous thromboembolism 1–2%. Chemical VTE prophylaxis, early mobilisation and TED stockings are standard.
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30-day mortality ~0.1–0.3%
In high-volume UK units, 30-day mortality after bariatric surgery is comparable to elective gallbladder surgery.
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Bile reflux, 3–10%
Biliopancreatic contents can back up into the pouch and oesophagus. Most cases are mild; a small minority need conversion to Roux-en-Y.
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Marginal ulcer, 5–10%
Ulcers at the anastomosis. Smoking, NSAIDs and aspirin are contraindicated for life. PPI cover is standard for six months.
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Nutritional deficiency — for life
Iron, B12, calcium, vitamin D and fat-soluble vitamins (ADEK) all need lifelong supplementation and annual bloods. This is not optional.
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Dumping and gallstones
Dumping is less common than after RYGB but does happen with sugar. Gallstones form in around 30% in the first year of rapid weight loss.
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Pregnancy — wait 12–18 months
Rapid weight loss and malabsorption make early pregnancy risky. Reliable contraception is essential in the first year to eighteen months.
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Red flags
Tachycardia, fever, severe abdominal or shoulder-tip pain in the first week — call the unit or go to A&E. Do not wait.
Reading your operation note
Your operation note in four parts. Read the last one first.
Whichever unit you go to, the note the bariatric surgeon sends you keeps to the same shape.
A quiet reminder
Surgical language is precise and can read coldly — we translate it for you.
If you would like us to talk you through the note before your review, just ask.
- 01 Header
Indication, BMI and operation chosen
Why the procedure was done — BMI, comorbidities, T2DM status — and why MGB was chosen over RYGB or sleeve.
- 02 Technique
Pouch length, limb length, anastomosis
The length of the gastric pouch, the biliopancreatic limb length (usually 150–200 cm), and how the gastro-jejunostomy was fashioned.
- 03 Findings
Leak test, liver, incidental findings
The result of the intra-operative leak test, appearance of the liver, and any incidental findings (hiatus hernia, adhesions).
- 04 Impression
Diet, vitamins, follow-up plan
Read this first: the staged diet, your lifelong vitamin regime, when to have bloods, and the follow-up schedule.
Recognised by major UK insurers
Cover for bariatric surgery varies significantly by insurer and by scheme — many corporate schemes exclude weight-loss surgery, some cover it once NICE criteria are met. We confirm cover in writing before booking.
Frequently asked
Everything we get asked about mini-gastric bypass.
Quick answers on how MGB compares with Roux-en-Y, weight-loss expectations, diabetes remission, and the lifelong vitamin regime.
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What is the difference between a mini-gastric bypass and a standard gastric bypass?
A mini-gastric bypass (MGB, also called one-anastomosis gastric bypass or OAGB) has one join between the stomach pouch and small bowel. A standard Roux-en-Y gastric bypass (RYGB) has two joins and a separate Roux limb. MGB is technically simpler, quicker, and often produces slightly greater weight loss; RYGB has longer-term data and less bile-reflux risk.
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How much weight will I lose after a mini-gastric bypass?
Most patients lose 30–40% of their total body weight in the first 12–24 months and sustain around 25–35% at five years. Weight-loss trajectory depends on starting BMI, dietary discipline and lifelong vitamin compliance — not on the operation alone.
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Will it put my type 2 diabetes into remission?
Type 2 diabetes remission is seen in 70–85% of patients in the first year, with roughly 50–60% still in remission at ten years. Newer-onset diabetes, lower HbA1c and not being on insulin all predict a better response.
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How much does a private mini-gastric bypass cost in the UK?
Roughly £11,000–£16,000 for laparoscopic MGB in a UK private hospital, or £13,000–£18,000 robotically. Revision surgery from a band or sleeve is more expensive. Some funded pathways exist within the NHS in England for eligible patients under NICE NG246.
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Is bile reflux really a risk?
It is the main disadvantage of MGB compared with RYGB. Clinically significant bile reflux occurs in 3–10% of patients; a small minority need conversion to a Roux-en-Y configuration. Severe pre-existing GORD or Barrett’s oesophagus makes RYGB the safer choice from the start.
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Will I need vitamins for the rest of my life?
Yes. A daily bariatric multivitamin, iron, vitamin B12 (oral or injection), calcium and vitamin D are needed for life, together with annual bloods. Nutritional non-compliance is the commonest long-term problem after any bypass operation, including MGB.
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How long is the recovery?
One or two nights in hospital, back to a desk job in two to four weeks, no heavy lifting for six weeks, and gym progression from six to eight weeks. The dietary progression (liquid → puree → soft → solid) also takes about six weeks.
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Can I get pregnant after a mini-gastric bypass?
Yes, but wait 12 to 18 months. Rapid weight loss and malabsorption in the first year risk maternal and fetal nutritional deficiency. Reliable contraception is essential in that window — bariatric surgery can also change the absorption of the oral contraceptive pill.
Related treatments
Looking for something else?
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Roux-en-Y gastric bypass
The long-established two-anastomosis alternative to MGB.
Learn more -
Gastric sleeve gastrectomy
Simpler stapled tube — no anastomosis, no bypass.
Learn more -
Duodenal switch
The most powerful — and most demanding — bariatric operation.
Learn more -
Gastric balloon
A non-surgical, temporary weight-loss option.
Learn more