“They Said It Was Just Gas Pain”: Weight Loss Surgery Complications and When a Bariatric Surgeon Can Be Sued

Surgical and hospital care guides · 16 min read · Published 10 November 2026 · Reviewed 10 November 2026 · Next review May 2027

By Dr Rosemary Listing, PhD (Law) · Medical negligence lawyer since 2014 · Of Counsel, Peter Evans & Associates

If you are reading this after weight loss surgery that went badly, or because you are still paying for it with your health years later, I want you to know that asking questions is not ungrateful and it is not an admission that you made a bad choice. Bariatric surgery helps many people. When it goes wrong, the early signs can be subtle, and what happens next matters enormously.

This guide is for anyone who has had, or is considering, weight loss surgery in Australia, and for the family who sat up with them. It covers the main operations, the early and late complications, the warning signs, the follow-up you should have for life, a recent NSW court decision, what your records should show, and how the law looks at it.

Start with your question

• Can a bariatric surgeon be sued for negligence?
• What are the main weight loss operations, and what can go wrong with each?
• What are the signs of a leak after a gastric sleeve or bypass?
• What problems can show up years later?
• What follow-up should I have, and for how long?
• What did the NSW Supreme Court decide in 2026?
• When is it an emergency?

The main operations

In 2023, sleeve gastrectomy made up about 80 per cent of first-time weight loss operations in Australia. One-anastomosis gastric bypass made up 11 per cent, and Roux-en-Y gastric bypass 9 per cent. The gastric band, once common, is now rarely used.¹

The problems shown in the diagram are those listed for each operation in a 2025 review in the Australian Journal of General Practice: staple line leak and bleeding after a sleeve, with reflux worsening over time; and leak and narrowing at the join after a bypass, with ulcers, internal hernias and dumping syndrome as later problems.¹

Before surgery: what you should be told

Bariatric surgery is usually offered to people with a body mass index over 40, or over 35 with serious conditions such as diabetes or heart disease, and usually after other approaches have been tried.² Before you agree, you should understand which operations are options for you, what each involves, the risks, and what life afterwards requires.

Questions to ask before surgery

• Which operation do you recommend for me, and why not the others?
• What are the risks of a leak, bleeding and further surgery with this operation?
• What will I need to do for the rest of my life: vitamins, blood tests, check-ups?
• What symptoms after surgery mean I should call you straight away, and on what number?
• Who looks after me if I have a complication at night or on a weekend?
• How will this affect my reflux, my medications, and any future pregnancy?

The first days and weeks

Serious early complications are uncommon. The national registry reports adverse events within 90 days, meaning an unplanned return to theatre, intensive care or hospital, in about 1.5 per cent of sleeve operations, 3.8 per cent of one-anastomosis bypasses and 4.8 per cent of Roux-en-Y bypasses. Deaths are rare, at about 0.04 per cent of first-time operations.¹ The registry also notes that once one complication occurs, the chance of further complications rises.³

Guidance written for Australian GPs lists abdominal pain, a fast heart rate, breathlessness and a drop in haemoglobin as the way surgical complications such as leaks, perforation, obstruction, infection and bleeding present, and says these symptoms should prompt urgent referral back to the surgical team. It adds that abdominal pain, nausea or vomiting should make a doctor consider these complications.⁴

That is the standard to hold in mind if you rang about pain and a racing heart and were told to wait for your routine appointment.

Expected, worth a call, or emergency

A general guide only. Your surgical team’s instructions come first.

Breathlessness and chest pain after any operation can also be signs of a blood clot. Our guide to missed blood clots explains those warning signs.

Months and years later

Some problems appear long after the wounds have healed. After a sleeve, reflux commonly worsens: one long-term study found 64 per cent of patients taking acid-suppressing medicine at ten years, compared with 12 per cent before surgery. After a Roux-en-Y bypass, ulcers at the join (more likely in smokers), internal hernias and dumping syndrome can occur. After a one-anastomosis bypass, acid and bile reflux can be a problem.¹

Nutritional deficiencies are common after bariatric surgery. The 2025 review lists deficiencies affecting more than one in ten patients, including iron, several B vitamins, vitamins A, C, D and E, magnesium, zinc and selenium.¹ Guidance for GPs warns that thiamine (vitamin B1) deficiency can cause neurological symptoms and, in severe cases, a brain condition called Wernicke’s encephalopathy.⁴

Follow-up for life

Healthdirect puts it simply: you should see your doctor for regular health checks and blood tests for the rest of your life following surgery, and you may need vitamins or supplements.² The 2025 review recommends daily multivitamins and yearly nutritional blood tests, and a gastroscopy to check for reflux damage one year after a sleeve or one-anastomosis bypass, then every two to three years.¹

Follow-up is a shared responsibility. Your surgeon and GP should tell you what is needed and arrange it. You need to turn up and take the supplements. When someone ends up seriously deficient, the questions are usually whether they were told, whether anyone was checking, and whether abnormal results were acted on.

What a 2026 NSW decision shows

In June 2026 the NSW Supreme Court decided a claim brought by a patient against a bariatric surgeon over an operation performed in 1999 (Campbell bht Mammoliti v Ritchie [2026] NSWSC 754).⁵ The operation was a biliopancreatic diversion, an older and more extensive procedure than those commonly performed today. The patient said he had not been warned of the risks, and that nutritional deficiencies after surgery had not been properly monitored and treated, causing him physical and psychiatric harm.

The Court found for the surgeon. The judgment’s summary records that the surgeon had acted in a manner widely accepted by peer professional opinion as competent professional practice, that the patient had been warned of the risks and side effects, and that the claim was brought out of time, with no suspension or extension of the limitation period.⁵

The decision does not mean bariatric claims can’t succeed. It does show, clearly, how these claims are judged:

• By the standards of the time. The question is what competent surgeons were doing when the surgery happened, not what we know now.
• By what was written down. Records made at the time, of warnings given and follow-up offered, carry great weight years later.
• Within time limits. Waiting many years, without a good explanation, can end a claim regardless of its merits.

If you felt dismissed when you raised concerns after surgery, see when being dismissed by a doctor becomes a legal issue.

What to look for in the records

Your records are often where the story becomes clear. You have a right to access your own health information. In NSW the Health Records and Information Privacy Act 2002 covers both public and private providers, and the Information and Privacy Commission explains how to ask.⁶ Our step-by-step guide to getting your medical records in Australia walks you through it.

How the law looks at it

A complication after weight loss surgery is not, on its own, negligence. Leaks, bleeding and deficiencies can happen even with excellent care. The legal questions are whether the advice, surgery and follow-up met the standard expected, and whether any shortfall caused you harm.

A claim usually turns on three questions: whether the care fell below what peers would widely accept as competent practice (section 5O of the Civil Liability Act 2002 (NSW))⁷, whether that shortfall probably caused harm you wouldn't otherwise have had (Tabet v Gett)⁸, and, where it matters, whether you were told the material risks first (Rogers v Whitaker)⁹¹⁰. Our guide to how a medical negligence claim works explains each one in plain terms.

In a bariatric case, the questions might be: was surgery, and this operation, appropriate for you? Was it performed competently? Were warning signs such as a fast heart rate acted on before and after discharge? When you called with symptoms, were you seen? Was long-term follow-up arranged, and were abnormal blood results acted on? As the 2026 Campbell decision shows, the standard is judged by accepted practice at the time of treatment.

In plain terms, the question is whether earlier recognition or better care would probably have avoided the harm, for example a shorter illness, fewer operations, or avoiding a lasting deficiency.

For weight loss surgery, that would usually include the risks of leak, bleeding and further surgery, the long-term effects such as reflux and nutritional deficiency, the need for lifelong supplements and monitoring, and the alternatives, including other operations and non-surgical options.

Who can claim, and when

The person who had the surgery can claim. If someone died, members of their family may be able to bring a claim. In NSW, time usually runs from when you knew, or ought to have known, enough to claim, not from the treatment itself, and courts can sometimes extend it, so an old injury may still count. See time limits in NSW or other states, and ask early.

More: complaint or claim? · how a claim is paid for · what a claim can cover

In my practice

When I read files about weight loss surgery, the operation itself is usually unremarkable. The story is in the days afterwards. A heart rate that is a little too fast on the morning of discharge. A phone call on a Friday night answered with reassurance. A weekend lost. By the time the leak is found, the person is far sicker than they needed to be. In the longer-term files, the pattern is quieter: a patient who drifted out of follow-up, blood tests that stopped after the second year, a deficiency that built slowly until it couldn’t be ignored. In both, it is rarely one dramatic failure. It is a chain of small ones, where each person assumed someone else was watching. And very often the patient blames themselves, for choosing surgery at all.

Both things can be true

Choosing weight loss surgery may have been the right decision for your health, and the care around it may still have let you down. Your surgeon may be highly skilled, and the warning signs afterwards may still have been missed. You can be glad of what the surgery gave you and still want answers about what it cost.

The bigger picture

Australia and New Zealand have a national Bariatric Surgery Registry, led by Monash University, which has recorded more than 180,000 procedures since 2012. Its 2023 report recorded the lowest number of Medicare-funded procedures since 2016, and found adverse event rates under 2 per cent for sleeve gastrectomy and under 5 per cent for first-time gastric bypass.³ That kind of data helps patients and surgeons see how safe these operations are across the country, and it is reasonable to ask your surgeon whether they contribute to it.

You can check your surgeon’s registration on the Ahpra public register,¹¹ and complaints about care in NSW can go to the Health Care Complaints Commission.¹² If a complication was recognised late, our guide to missed and delayed diagnosis may help, and for infection that spirals, see sepsis and when it becomes negligence.

Support

You don't have to work through this alone. These services can help:

• Lifeline, 24-hour crisis support: 13 11 14 (listed on healthdirect's helplines page)¹³
• Beyond Blue, anxiety and depression support: 1300 22 4636
• Medicare Mental Health, help finding mental health support: 1800 595 212
• healthdirect, 24-hour nurse advice: 1800 022 222
• Health Care Complaints Commission (NSW): 1800 043 159

A woman who walked laps of her hallway watching the number on her wrist now knows what it meant, and that she was right to call. You deserve that clarity too.

With care,
Rosemary

Frequently asked questions