Bariatric surgery · London
SADI-S, by a specialist bariatric surgeon.
The strongest mainstream operation for super-obesity and type 2 diabetes - a sleeve gastrectomy plus a single duodeno-ileal anastomosis, delivered in an MBOS-accredited unit with lifelong follow-up priced in.
Why patients choose us
- 01
A named MBOS-accredited bariatric surgeon
Not a general list. A high-volume SADI-S operator in a unit with a full MDT: obesity physician, dietitian, psychologist, endocrinologist and anaesthetist.
- 02
The right operation for you
SADI-S is not always the answer. For lower BMI or milder metabolic disease, sleeve or Roux-en-Y bypass may fit better. We tell you honestly before you commit.
- 03
Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Indicative pricing
What a private SADI-S costs in London.
Indicative ranges across our partner units. Send us your background and we quote firm figures across two or three options, with year-one follow-up costed separately.
In short
A primary SADI-S in our London network: £22,000-£38,000, home in 2 to 3 days.
| Stage | Indicative range | Typical duration | Turnaround |
|---|---|---|---|
| Initial MDT assessment and workup | £1,800-£2,800 | 2-4 weeks | Report in 5 days |
| Primary SADI-S (all-inclusive: surgeon, anaesthetist, theatre, 2-3 nights) | £22,000-£38,000 | 2-3 h theatre | Discharge day 2-3 |
| Revision sleeve gastrectomy to SADI-S | £24,000-£42,000 | 2.5-4 h theatre | Discharge day 2-4 |
| Year-one follow-up package (dietitian, labs, DEXA) | £1,600-£2,600 | 12 months | Included in most quotes |
| Second-opinion review of prior bariatric records | £300-£500 | 45 min | 48 hours |
Prices vary by unit, by which surgeon operates, by whether robotic access is used, and by revision complexity. Year-one follow-up is included in most of our quotes.
The journey
From first enquiry to lifelong follow-up - what happens, in order.
One team from first message to your annual review - MDT workup, surgery, dietitian, endocrinology and labs.
- 01
Before
You send us your background
A short, confidential form. Weight and height, comorbidities (T2DM, HTN, OSA, NAFLD), prior bariatric surgery if any, and current medications.
- 02
Before
We come back with a recommendation
Within one working day: whether SADI-S fits, or whether sleeve, RYGB or a GLP-1 pathway is a better call. Indicative price. An honest read either way.
- 03
Before
MDT workup
Bariatric surgeon, obesity physician, dietitian, psychologist and anaesthetist. UGI endoscopy, HbA1c, LFT, lipids, baseline vitamins (D, B12, iron, zinc, copper, selenium), DEXA and OSA screen.
- 04
On the day
Admission and anaesthesia
Arrival, consent, VTE prophylaxis and antibiotics. General anaesthesia, laparoscopic or robotic five-port access. Around 2 to 3 hours in theatre.
- 05
On the day
The SADI-S itself
Sleeve gastrectomy over a 36 to 40 Fr bougie, transection of the first part of the duodenum, single omega-loop anastomosis to ileum 250 to 300 cm from the ileocaecal valve. Mesenteric defects closed. Drain 24 to 48 h.
- 06
On the day
Ward and early mobilisation
2 to 3 day admission. Sips of water day 0, free fluids day 1, purees on discharge. Early walking to reduce VTE risk. Written aftercare and 24/7 contact.
- 07
After
Lifelong nutritional monitoring
Dietitian at 2, 6, 12 weeks then 3-monthly for year one. Comprehensive labs at 3, 6, 12 months, then annually. DEXA at 12 months. Non-negotiable, and priced in.
When it helps
When SADI-S is the right step - and when it is not.
The patients we see most, plus the clinical situations where SADI-S is the wrong operation and sleeve, RYGB or a GLP-1 pathway fits better.
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BMI 50 or above (super-obesity)
The greatest excess weight loss of any mainstream bariatric operation. Best studied indication for primary SADI-S.
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BMI 40+ with type 2 diabetes
Highest remission rate of any bariatric procedure - 85 to 95% off medication at one to two years in most series.
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Revision after failed sleeve
Insufficient weight loss or weight regain after sleeve gastrectomy, or recurrent T2DM. Converting to SADI-S adds a malabsorptive limb without a second anastomosis.
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High metabolic burden
NAFLD/NASH, dyslipidaemia, OSA, hypertension - SADI-S delivers deep and durable improvement across all four.
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Not for you: severe GORD or Barrett’s
A sleeve component makes reflux worse. If you have severe GORD or Barrett’s oesophagus, Roux-en-Y bypass is the safer operation.
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Not for you: known IBD or short bowel
Malabsorption on top of Crohn’s, coeliac or a short bowel is dangerous. We refer these patients away from SADI-S.
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Not for you: unable to commit to lifelong follow-up
Protein-energy malnutrition and vitamin deficiencies are real. SADI-S is only safe if you will attend labs and take supplements for life.
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Red flag: active eating disorder or untreated addiction
These need to be stabilised with the psychology team before any bariatric operation. We say so honestly.
Procedure options
SADI-S sits within a family of bariatric options.
What each option involves, and how weight loss, T2DM remission and nutritional impact compare.
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SADI-S (single-anastomosis duodeno-ileal + sleeve)
Sleeve gastrectomy plus one omega-loop anastomosis to ileum, 250 to 300 cm common channel. Mean 85 to 90% excess weight loss at 5 years, T2DM remission 85 to 95%.
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Traditional duodenal switch (BPD-DS)
Two anastomoses instead of one. Similar weight loss to SADI-S but higher operative risk and more internal-hernia potential. Rarely offered as primary.
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Sleeve gastrectomy (SG)
Restrictive only, no anastomosis, no malabsorption. 60 to 70% excess weight loss, T2DM remission 40 to 60%, minimal nutritional impact. Sometimes staged before SADI-S.
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Roux-en-Y gastric bypass (RYGB)
Small pouch plus 100 to 150 cm Roux limb. 65 to 75% excess weight loss, T2DM remission 75 to 80%, moderate nutritional impact, kinder to GORD than sleeve or SADI-S.
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Revision SG to SADI-S
A single-stage add-on for patients who have plateaued after sleeve. Adds malabsorption without disturbing the sleeve.
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GLP-1 programme (Wegovy, Mounjaro)
Non-surgical route for lower BMI or as a bridge. 15 to 22% total body weight loss on drug, effect wanes on stopping. Not a substitute for surgery in super-obesity.
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Endoscopic sleeve gastroplasty (ESG)
Endoscopic, no incisions, 15 to 20% total body weight loss. Suits BMI 30 to 40 without severe metabolic disease.
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Second-opinion review
Independent review of your prior bariatric records and current labs. Sometimes the answer is optimise, not re-operate.
Our vetted London network
A small panel of bariatric surgeons, we picked them.
MBOS-accredited consultant bariatric surgeons operating at King’s Bariatric Private Surgery, Chelsea and Westminster Private Bariatric, HCA The Wellington Bariatric Sciences, Imperial Private at Charing Cross, and Cromwell BUPA Bariatric. Introductions are made privately, once we understand your case.
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MBOS-accredited bariatric surgeons with high SADI-S case volumes
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Full MDT: obesity physician, dietitian, psychologist, anaesthetist, endocrinologist
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Hepatology and sleep pathways for NAFLD and OSA workup
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Lifelong follow-up with 3, 6, 12 month labs, then annual review and DEXA
Safety and recovery
What to expect afterwards - honestly.
SADI-S is a well-established bariatric operation. The things worth planning are your anaesthetic, the leak window, the lifelong supplements, and the follow-up rhythm.
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General anaesthesia, laparoscopic or robotic
GA delivered by a consultant anaesthetist. Robotic access in selected units. Around 2 to 3 hours in theatre, 2 to 3 nights on the ward.
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Bleeding (2%) and staple-line leak (1-2%)
The two commonest early complications. Most bleeding settles with observation; a leak may need re-laparoscopy, drainage or stenting.
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VTE prophylaxis
Enoxaparin from admission until 10 to 14 days after discharge, plus early mobilisation and compression stockings. Baseline VTE risk 1%.
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Internal hernia - rarer than after RYGB
Single anastomosis and closed mesenteric defects reduce, but do not abolish, the risk. Any late abdominal pain with vomiting needs a same-day CT.
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Marginal ulcer at the duodeno-ileal anastomosis
3 to 5% at 2 years. PPI cover for 12 months, no smoking, no NSAIDs - these three rules matter.
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Dumping and post-prandial hypoglycaemia
Common in the first year, usually settles with slow eating and low-glycaemic-index meals. Persistent hypoglycaemia needs endocrine review.
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Diarrhoea and malodorous flatus
30 to 50% of patients report this in the first 6 to 12 months, driven by fat malabsorption. Most adapt; a longer common channel is an option at revision.
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Gallstones and ursodeoxycholic acid
Rapid weight loss precipitates gallstones. We prescribe ursodeoxycholic acid for 6 months to reduce the rate of symptomatic cholelithiasis.
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Red flags after discharge
Persistent tachycardia, fever, abdominal pain out of keeping with recovery, vomiting or shortness of breath - call the unit or go to A&E the same day.
Reading your operation note
Your SADI-S note in four parts. Read the last one first.
Whichever surgeon operates, the note keeps to the same shape.
A quiet reminder
Bariatric language is precise - we translate it for you.
If you would like us to talk you through the note before your dietitian review, just ask.
- 01 Anatomy
Sleeve size and common channel length
Bougie size used (36 to 40 Fr), sleeve staple line and the common channel measured back from the ileocaecal valve (typically 250 to 300 cm).
- 02 Technique
Access, anastomosis, closure
Laparoscopic or robotic five-port access, hand-sewn or stapled duodeno-ileal anastomosis, mesenteric defects closed, leak test result, drain placement.
- 03 Findings
Intra-operative issues and haemostasis
Any bleeding, adhesions, incidental hiatus hernia repair, and the surgeon’s judgement on whether the anatomy was straightforward.
- 04 Impression
Nutrition, follow-up and safety-netting
Read this first: PPI for 12 months, lifelong multivitamin plus iron, calcium citrate, vitamin D 5000 IU, B12, ADEK, when to be back for labs, and red flags.
Recognised by major UK insurers
Bariatric cover varies by insurer and by BMI/comorbidity threshold - many policies exclude weight-loss surgery. We confirm cover before booking.
Ready when you are
Talk to a specialist bariatric surgeon this week.
Send your BMI, comorbidities and any prior bariatric records. We come back within one working day with an honest recommendation and firm figures.
Frequently asked
Everything we get asked about SADI-S.
Quick answers on candidacy, comparison with sleeve and RYGB, cost and the lifelong nutritional side.
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What is SADI-S and how does it differ from traditional duodenal switch?
SADI-S stands for Single Anastomosis Duodeno-Ileal bypass with Sleeve gastrectomy. It is the modern evolution of the classical duodenal switch (BPD-DS). Traditional DS has two anastomoses (Roux and jejuno-jejunal); SADI-S uses one omega-loop connection between the divided duodenum and a loop of ileum 250 to 300 cm from the ileocaecal valve. Same principle - restriction from the sleeve plus malabsorption from the diverted small bowel - with a shorter operation, fewer anastomoses to leak, and less internal-hernia risk.
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Am I a candidate for SADI-S?
The best-studied indications are BMI 50 or above (super-obesity), and BMI 40 or above with type 2 diabetes on medication. It is also used as a revision after a sleeve gastrectomy that has failed to deliver enough weight loss or in which T2DM has recurred. You are not a candidate if you have severe GORD or Barrett’s, inflammatory bowel disease, previous small-bowel resection, an untreated eating disorder or cannot commit to lifelong follow-up and supplements.
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How does SADI-S compare with sleeve gastrectomy and Roux-en-Y bypass?
On weight loss and diabetes remission SADI-S is the strongest of the three: around 85 to 90% excess weight loss and 85 to 95% T2DM remission at 5 years. Sleeve gives 60 to 70% EWL and 40 to 60% T2DM remission, with the least nutritional impact. Roux-en-Y gives 65 to 75% EWL and 75 to 80% T2DM remission, with moderate nutritional impact and better GORD control. SADI-S trades that extra weight loss for a heavier lifelong nutritional commitment.
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What does the aftercare actually involve?
For life: a daily bariatric multivitamin, iron, calcium citrate 1200 to 1500 mg, vitamin D 5000 IU, oral or injectable B12, and fat-soluble vitamins A, D, E and K taken with a fat-containing meal. Protein target 90 to 100 g/day. PPI for 12 months. Labs at 3, 6 and 12 months then annually (FBC, U&E, LFT, HbA1c, ferritin, folate, B12, vitamin D, calcium, zinc, copper, selenium, PTH). DEXA at 12 months and 3-yearly thereafter.
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What is the risk of malnutrition and vitamin deficiency?
Real and lifelong. Protein-energy malnutrition is uncommon (under 5%) if you meet your protein target and attend follow-up. Vitamin D, iron, B12, calcium and the fat-soluble vitamins A, D, E and K are the ones we watch most closely - deficiencies of these are common if supplements are skipped. Compliance is the single biggest predictor of a safe long-term result, which is why we price follow-up in and refuse to book patients who cannot commit to it.
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How much does a private SADI-S cost in the UK?
Roughly £22,000 to £38,000 for a primary SADI-S all-inclusive (surgeon, anaesthetist, theatre, 2 to 3 nights in hospital), and £24,000 to £42,000 for a revision from sleeve to SADI-S. The first year of follow-up (dietitian, comprehensive labs, DEXA) is £1,600 to £2,600. We confirm a firm figure within one working day.
Related treatments
Looking for something else?
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GLP-1 weight-loss clinic
Wegovy and Mounjaro programmes with clinician oversight.
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Wegovy (semaglutide)
Structured semaglutide programme for weight loss.
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Allurion swallowable balloon
Non-surgical, non-endoscopic gastric balloon.
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Endoscopic sleeve gastroplasty (ESG)
Endoscopic sleeve without incisions or malabsorption.
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TORe (transoral outlet reduction)
Endoscopic revision for weight regain after RYGB.
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Obesity
Condition guide: assessment and treatment pathways.
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Type 2 diabetes
Condition guide: medical and metabolic-surgery routes.
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Send Enquiry
Tell us your background and we come back within a working day.
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