Bariatric MDT · United Kingdom
Jejunoileal bypass — a historical operation, a very modern conversation.
The jejunoileal bypass was abandoned decades ago because of severe complications. If you had one, you need lifelong specialist follow-up. If you are researching bariatric surgery today, you deserve a modern operation — and an honest conversation about which one fits you.
Why patients choose us
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A consultant bariatric MDT, not a walk-in
A named bariatric surgeon, a hepatologist and a nephrologist reviewing your case together — not a booking clerk with a price list.
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Historical operation, modern management
Jejunoileal bypass has not been performed in the UK for decades. We help patients who still live with it, and steer newcomers to safer modern options.
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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 bariatric assessment and surgery costs privately in the UK.
Indicative ranges across our partner clinics. Send the details and we quote firm figures across two or three options.
In short
A modern sleeve gastrectomy in our network: £10,000–£14,000, home in 1–2 nights.
| Procedure | Indicative range | Typical duration | Recovery |
|---|---|---|---|
| Post-JI-bypass MDT assessment | £1,800–£3,500 | Half-day | 10–14 days for reports |
| Revision of JI bypass (take-down or conversion) | £18,000–£32,000 | 3–5 h in theatre | 3–5 nights inpatient |
| Roux-en-Y gastric bypass (primary) | £12,000–£16,000 | 2–3 h | 2–3 nights inpatient |
| Sleeve gastrectomy (primary) | £10,000–£14,000 | 1–2 h | 1–2 nights inpatient |
| Duodenal switch / SADI-S | £14,000–£18,000 | 3–4 h | 2–3 nights inpatient |
| Bariatric consultation only | £250–£450 | 45 min | Same visit |
Prices vary by clinic, by which surgeon does the case, and by the complexity of the operation — a revision of a JI bypass is not the same as a primary sleeve. We come back with a firm quote within one working day.
The problem
One name, two very different patients.
People typing “jejunoileal bypass” into a search box are usually one of two people. Someone who had the operation forty years ago and is now unwell — or someone researching bariatric surgery today and reading history by accident. Both deserve a proper answer.
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Had a JI bypass in the ’70s?
You need a full bariatric MDT workup — nutrition, liver, kidney, bone — and a plan about whether to reverse it or convert it.
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Worried about complications?
Cirrhosis, kidney stones, malnutrition and joint pain are all recognised late complications. None of them are dismissed as “just ageing”.
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Considering bariatric surgery today?
Modern operations are nothing like a JI bypass. We arrange the right one — sleeve, Roux-en-Y or duodenal switch — with a consultant surgeon.
The journey
From enquiry to lifelong follow-up — what happens, in order.
One clinician from first message to review — with a full MDT behind them.
Phase 1 · Before your procedure
Concierge, off-stage for you
Phase 2 · On the day
A few hours at the clinic
Phase 3 · After
Concierge, back on
- 01
Before
You tell us what is going on
A short, confidential form. Whether you had a JI bypass years ago, or you are researching bariatric surgery for the first time.
- 02
Before
We come back with a recommendation
Within one working day: for prior JI bypass — a full workup and MDT plan. For new patients — the modern operation that fits your BMI, comorbidities and goals.
- 03
Before
We arrange the appointment
Usually within one to two weeks. Bloods, imaging and specialist input arranged in the right order, and you are told exactly what to expect.
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On the day
Arrival at the clinic
Arrival, consent and a proper conversation with the bariatric surgeon. Nothing is done that day you did not agree to in writing beforehand.
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On the day
Assessment or procedure
Either the workup for a prior JI bypass, or a modern bariatric operation in a licensed theatre by a consultant surgeon and anaesthetist.
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On the day
Home, or an inpatient stay
Investigations are day-case. Modern bariatric surgery is one to three nights on the ward, with an enhanced-recovery pathway.
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After
Lifelong follow-up
Prior JI bypass patients need lifelong nutrition, liver and kidney surveillance. Modern bariatric patients need structured follow-up for at least two years, then annual bloods.
Typical end-to-end: 2–3 weeks from enquiry to assessment. Bariatric follow-up: lifelong.
When it helps
When a bariatric MDT review is the right step.
The situations we see most, plus the one red flag that means an emergency rather than an appointment.
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Prior JI bypass, feeling unwell
Fatigue, diarrhoea, joint pains or abnormal liver blood tests years or decades after a jejunoileal bypass in the 1970s or ’80s.
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Prior JI bypass, abnormal LFTs
Chronically deranged liver tests, cirrhosis on scan, or hepatic decompensation — often driven by bacterial overgrowth in the blind loop.
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Prior JI bypass, kidney stones
Recurrent calcium-oxalate renal calculi, nephrocalcinosis or falling eGFR from enteric hyperoxaluria — a well-recognised late complication.
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Prior JI bypass, malnutrition
Low albumin, deficiencies of iron, B12, folate, calcium, magnesium or fat-soluble vitamins (A, D, E, K), and metabolic bone disease.
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Prior JI bypass, immune-complex symptoms
Migratory arthritis, skin rashes or a pustular dermatitis — the bypass-arthritis-dermatitis syndrome, driven by bacterial antigens from the blind loop.
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Considering bariatric surgery today
A different conversation entirely — modern operations are safe, well-studied and nothing like a JI bypass. We arrange the right one for you.
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Weight regain after old bariatric surgery
Whether you had a JI bypass, an old gastric band or a small-pouch bypass, a modern revision or conversion is often the sensible next step.
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Red flag: jaundice, ascites or confusion
Yellowing of the skin, a swelling abdomen or confusion in a JI-bypass patient is hepatic decompensation — same-day A&E, not a clinic booking.
Procedure options
The modern operations that replaced the JI bypass.
What each option on the table actually involves — and which fits which problem.
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Roux-en-Y gastric bypass
The modern gold-standard bypass. A small gastric pouch is joined to a limb of jejunum, restricting food and modestly reducing absorption — with none of the JI-bypass blind loop.
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Sleeve gastrectomy
About 75–80% of the stomach is removed, leaving a narrow sleeve. Purely restrictive, no rerouting of bowel, and the most commonly performed bariatric operation in the UK.
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Duodenal switch / SADI-S
A sleeve combined with a duodeno-ileal bypass. More weight loss and better diabetes remission than a Roux-en-Y, at the cost of tighter nutritional follow-up.
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Adjustable gastric band
A silicone band placed around the upper stomach, adjusted through a subcutaneous port. Rarely offered today — most units prefer sleeve or bypass.
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Endoscopic sleeve gastroplasty
Endoscopic sutures narrow the stomach without cutting. A non-surgical option for lower BMIs or patients not ready for a laparoscopic operation.
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Intragastric balloon
A silicone balloon placed endoscopically and left for six or twelve months. Modest, temporary weight loss — a bridge, not a definitive answer.
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Take-down of JI bypass
Reversal of the historical bypass, restoring normal small-bowel continuity. Often the right operation if malnutrition or liver disease is progressing.
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Conversion of JI bypass
The old anatomy is taken down and a modern operation — usually a Roux-en-Y or duodenal switch — is fashioned in the same sitting, if weight control is still needed.
Our vetted UK network
A small panel of bariatric surgeons, we picked them.
Consultant bariatric surgeons across London, Manchester and Birmingham, with hepatology and nephrology on speed dial. Not listed publicly — introductions are made privately, once we understand your case.
Selection criteria
How we choose every surgeon in our network.
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Consultant bariatric surgeons on the BOMSS specialist register
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MDT input from hepatology and nephrology for prior JI bypass patients
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Specialist bariatric dietitian and metabolic-bone follow-up
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Enhanced-recovery pathways and audited outcomes for revision surgery
Safety and long-term care
Why JI bypass was abandoned — and what modern management looks like.
The complications are not obscure trivia — they still matter for patients living with a JI bypass today. The other side of the coin is that modern bariatric surgery is genuinely different.
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Why JI bypass was abandoned
Blind-loop bacterial overgrowth drives hepatic dysfunction and cirrhosis, immune-complex arthritis and dermatitis, and severe malabsorption. The morbidity was unacceptable — modern operations do not work this way.
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Enteric hyperoxaluria and the kidneys
Fat malabsorption leaves calcium bound to fat in the gut; free oxalate is absorbed, deposited in the kidneys, and causes calcium-oxalate stones, nephrocalcinosis and progressive renal failure.
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Protein-calorie malnutrition
Low albumin, muscle wasting and oedema are common late findings. A structured dietetic assessment is the first step in any prior-JI-bypass review.
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Fat-soluble vitamin deficiency
Vitamins A, D, E and K are all poorly absorbed. Night blindness, osteomalacia, neuropathy and easy bruising are classic — replacement is lifelong.
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Metabolic bone disease
Low vitamin D, low calcium and secondary hyperparathyroidism drive osteomalacia and osteoporosis. A DEXA scan belongs in every workup.
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Modern bariatric surgery is different
Roux-en-Y bypass, sleeve gastrectomy and the duodenal switch do not create a blind loop and are supported by decades of outcome data — a very different risk profile.
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Consider revision surgery
Take-down of a JI bypass, or conversion to a modern operation, is the definitive answer for progressive complications. The decision is made by an MDT, not a single surgeon.
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Lifelong supplementation
Multivitamin, vitamin D, calcium, vitamin K, iron and vitamin B12 are the baseline — adjusted to your bloods, and never stopped without specialist advice.
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Red flags
Jaundice, ascites, confusion, heavy weight loss, fractures or falling urine output are not normal — same-day medical review, not a routine appointment.
Reading your workup letter
Your MDT letter in four parts. Read the last one first.
Whether you are being reviewed after a historical JI bypass or worked up for a modern operation, the summary letter tends to keep to the same shape.
A quiet reminder
Bariatric language is precise and can read coldly — we translate it for you.
If you would like us to talk you through the letter before your review, just ask.
- 01 Header
Original operation and current anatomy
What was done in the 1970s or ’80s — the length of jejunum and ileum in continuity, the site of the anastomosis, and the length of the blind (bypassed) limb.
- 02 Bloods
Nutrition, liver and kidney panel
Albumin, PT/INR, LFTs, vitamins A, D, E and K, B12, folate, iron studies, calcium, magnesium, phosphate, PTH, eGFR and a 24-hour urine oxalate.
- 03 Imaging
Liver, bone and kidney assessment
FibroScan or liver biopsy for fibrosis, DEXA for bone density, renal ultrasound for stones or nephrocalcinosis, and cross-sectional imaging when the anatomy is unclear.
- 04 Impression
Plan — supplementation, surveillance, surgery
Read this first: the supplement regimen, the surveillance interval, and whether revision surgery (take-down or conversion) is being recommended by the MDT.
Recognised by major UK insurers
Cover for bariatric assessment and surgery varies by insurer and by indication — usually funded when medically indicated, with strict BMI and comorbidity criteria. Revision surgery is considered case-by-case. We confirm cover before booking.
Frequently asked
Everything we get asked about jejunoileal bypass.
Quick answers on the historical operation, its late complications, and what modern UK bariatric care looks like.
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What is a jejunoileal bypass?
A historical bariatric operation, performed in the 1960s to early 1980s, in which the first 14 inches of jejunum were joined directly to the last 4 inches of ileum, leaving the intervening small bowel as a long blind loop. It caused extreme malabsorption and dramatic weight loss — but at unacceptable cost.
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Why was the jejunoileal bypass abandoned?
Because of severe late complications: hepatic dysfunction and cirrhosis from bacterial overgrowth in the blind loop, calcium-oxalate kidney stones and renal failure from enteric hyperoxaluria, protein-calorie malnutrition, fat-soluble vitamin deficiencies, metabolic bone disease, immune-complex arthritis and dermatitis, chronic diarrhoea, pancreatitis, and death. Roux-en-Y gastric bypass replaced it.
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I had a JI bypass decades ago — what should I do now?
Ask your GP for referral to a bariatric MDT, or come to us. You need a comprehensive nutrition workup, LFTs and a FibroScan, kidney function and a 24-hour urine oxalate, and a DEXA scan. Many patients need take-down surgery or conversion to a modern operation, and all need lifelong supplementation.
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What is the modern equivalent of a JI bypass?
There is no direct equivalent, because the JI bypass was too dangerous. The modern operations that achieve similar weight loss are the Roux-en-Y gastric bypass, the sleeve gastrectomy, and the duodenal switch / SADI-S — none of which create a blind loop, and all of which are supported by strong long-term outcome data.
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Can a jejunoileal bypass be reversed?
Yes. The old anatomy can be taken down and normal small-bowel continuity restored — either alone, if malnutrition or liver disease dominates, or with conversion to a modern bariatric operation in the same sitting if weight control is still needed. It is major surgery and belongs in a specialist unit.
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What supplements should a prior JI bypass patient take?
As a baseline, a bariatric-strength multivitamin, vitamin D, calcium, vitamin K, iron and vitamin B12 — adjusted to your bloods and reviewed at least annually. Never stop supplementation without specialist advice, even if you feel well.
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I want bariatric surgery today — should I be worried about JI bypass?
No. Jejunoileal bypass has not been offered in the UK for decades and no reputable surgeon would recommend it. A modern UK bariatric MDT will discuss sleeve gastrectomy, Roux-en-Y gastric bypass and duodenal switch — all safe, well-studied and nothing like the operation of the 1970s.
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