Two-thirds of patients thought to be suffering from acid reflux do not actually have the condition, a landmark study has revealed, raising serious questions about the widespread prescribing of stomach-acid drugs across the NHS.
The research, led by the Functional Gut Clinic, examined more than 700 people across six NHS trusts who were already taking medication for suspected gastro-oesophageal reflux disease (GORD). The findings were stark: only one in three participants met the diagnostic criteria for the condition, meaning 66 per cent displayed normal acid exposure levels.
Professor Anthony Hobson, the clinic’s director and an internationally recognised clinical gastrointestinal scientist, said the results suggest that “there could be a significant number of patients in the UK who have been misdiagnosed with GORD”. With an estimated 10 million adults currently taking medication for persistent reflux, the figures imply that roughly six million Britons may be receiving unnecessary treatment.
The scale of unnecessary prescribing places a heavy financial burden on the NHS. Proton pump inhibitors (PPIs) — the most common class of acid-blocking medication — cost the health service approximately £190 million each year. Between five and 10 million people receive PPI prescriptions annually, yet current NHS protocols mean only one in 12 patients undergo formal testing before treatment begins. The Functional Gut Clinic notes that a very small percentage of NHS patients are referred for diagnostic reflux tests; the majority are treated based on suspicion alone.
Consequences of misdiagnosis for patient health
Professor Hobson warned that for many patients, PPIs have become a “patch-over” solution that merely suppresses symptoms while eliminating 80 per cent of stomach acid. This approach, he cautioned, can have “profound effects” on the gut’s microbiome, potentially increasing susceptibility to stomach infections among people who do not actually have excessive acid production.
Long-term PPI use is associated with decreased bacterial richness and profound changes in the gut microbiota, according to research in the field. Oral bacteria and potentially pathogenic organisms can increase in the gut of PPI users, leading to an imbalance in the microbial community known as dysbiosis. This disruption elevates the risk of enteric infections, including Clostridium difficile.
Beyond microbiome disruption, chronic PPI use can impair vitamin B12 absorption because stomach acid is needed to release the vitamin from food. Symptoms of deficiency include loss of concentration, fatigue and lightheadedness, and persistent deficiency may lead to neurological disorders, depression and dementia. While some studies show no association between long-term PPI use and B12 deficiency when assessing specific biomarkers, others indicate a significant risk, particularly in men aged 18 to 40 and in those taking PPIs for more than six months.
Dr Hugh Coyne, a GP and co-founder of Coyne Medical, warned that reducing stomach acid unnecessarily can also heighten the risk of pneumonia. One study found a 73 per cent increased risk of pneumonia during PPI-exposed periods, with the risk highest in the first month of treatment. Another study reported a 42 per cent increased risk of developing pneumonia among regular PPI users. The proposed mechanism involves PPI-induced changes to the gut and oral microbiome, potentially leading to micro-aspiration of an altered microbiome.
Other potential risks associated with long-term PPI use include fractures, particularly in the elderly; low magnesium levels (hypomagnesaemia); subacute cutaneous lupus erythematosus; and, according to some research, liver disease, dementia and renal disease.
The reliance on medication also discourages lifestyle modifications, despite obesity and alcohol consumption being primary contributors to genuine reflux. Dr Coyne advised that PPIs should only be taken when genuinely needed, at the correct dose and for the appropriate duration. He urged patients experiencing difficulty swallowing, unintentional weight loss, gastrointestinal bleeding or persistent vomiting to consult their doctor promptly, as these symptoms warrant further investigation regardless of whether medication appears effective.
Professor Hobson emphasised the broader consequences of misdiagnosis. “Millions of people have these symptoms and the effects they have on quality of life, workplace absenteeism and longevity can be devastating,” he said. “If you can pinpoint the reasons and get an effective treatment so that reflux is no longer causing symptoms or damage, that can have a huge impact.”
Cost to NHS resources and diagnostic backlogs
Under current NICE guidelines, reflux testing is typically reserved for patients who have not responded to an initial course of PPIs. However, some NHS trusts now face testing backlogs exceeding 12 months, leaving patients dependent on repeated medication courses without a proper diagnosis. The COVID-19 pandemic has significantly exacerbated these backlogs, particularly for endoscopic procedures, with potential delays of over a year in some regions.
A spokesman for the Department of Health and Social Care acknowledged patient frustrations regarding diagnostic delays, noting that record levels of diagnostic activity had been delivered over the past year. The department highlighted significant investment in new and upgraded Community Diagnostic Centres nationwide, and said waiting lists are now at their lowest point in three years.
Alternative diagnoses mistaken for acid reflux
Experts believe the remaining patients who do not have GORD are likely experiencing entirely different ailments that present with similar symptoms. Small Intestinal Bacterial Overgrowth (SIBO) emerged as one probable alternative diagnosis. SIBO occurs when excessive bacteria build up in the small intestine, and symptoms can include bloating, excessive wind, abdominal pain, diarrhoea or constipation, fatigue and unintentional weight loss. Low stomach acid — or the use of acid-suppressing medication — is itself a contributing factor to SIBO. The condition is typically diagnosed using a hydrogen or methane breath test, and treatment options include antibiotics, dietary changes such as a low-FODMAP diet, and managing underlying conditions.
Functional heartburn and oesophageal hypersensitivity were also identified as conditions frequently mistaken for genuine acid reflux. In these cases, patients experience the sensation of burning or discomfort without actual acid exposure, and PPIs provide no therapeutic benefit.
For the minority of patients who do have confirmed GORD, alternative approaches may be more effective than lifelong medication. Dr Paul Goldsmith, a gastrointestinal surgeon at Manchester University NHS Foundation Trust, noted that approximately 15 per cent of patients with confirmed GORD have underlying conditions such as hernias. For these individuals, surgical intervention may prove more beneficial than prolonged reliance on PPI medication, potentially offering a more permanent resolution to symptoms. Procedures such as fundoplication surgery aim to strengthen the valve between the oesophagus and stomach, and newer options like the LINX procedure are also being explored.