Non-invasive endometriosis tests enter UK trials, promising faster diagnosis

Endometriosis affects approximately one in ten women of reproductive age, yet diagnosis remains notoriously slow. The condition, in which uterine-like tissue grows outside the uterus, causes severe pelvic pain, painful intercourse, bowel and bladder issues, and reduced fertility. Current diagnosis relies on symptom assessment, physical examination, specialist imaging and often laparoscopic surgery.

The two tests now under evaluation in the UK – Endotest (saliva) and EndoSure (gut electrical activity) – are designed to be used in primary care, potentially allowing GPs to identify endometriosis months or years earlier than currently possible.

Endotest analyses saliva for specific microRNAs – small molecules that regulate gene expression. A French study of 971 patients reported high accuracy, but critics note that most participants already had confirmed endometriosis, unlike the general GP population where pelvic pain has many possible causes. EndoSure uses sensor pads on the abdomen to detect electrical signals from the gut over 45 minutes. A study of 154 women reported 95% sensitivity and 96% specificity, though again in a selected population.

In Australia, neither test is currently available, and the UK trials are the first time either has been tested in a real-world primary care setting. The results, expected over the next three years, will be crucial in determining whether these tools can reliably distinguish endometriosis from other causes of pelvic pain.

“The hope is that these tests will give GPs a quick, non-invasive way to start the diagnostic process,” said Associate Professor Mathew Leonardi, a gynaecological surgeon at McMaster University who co-authored the article outlining the trials. “But we need to see how they perform in the messy reality of everyday clinical practice – where patients may have bowel disorders, bladder conditions or muscular pain that mimic endometriosis.”

Clinicians also point out that a positive test does not replace the need for confirmatory imaging or surgery, and that the cost and availability of the tests remain uncertain. The National Institute for Health and Care Excellence (NICE) in the UK has approved the trials but has not endorsed the tests for routine use.

Patient advocates have welcomed the development. “Anything that can shorten the average seven-year wait for diagnosis is a step forward,” said a spokesperson for Endometriosis Australia. “But we need to make sure these tests are accessible, affordable, and backed by strong evidence before they become the new standard.”

Why This Matters

Faster diagnosis reduces suffering: The typical seven-to-nine-year diagnostic delay means years of avoidable pain, repeated specialist visits, and emotional distress. A simple GP-administered test could transform this timeline.
Economic impact: Endometriosis costs health systems and economies billions annually through lost productivity, treatment costs, and disability. Earlier detection could reduce these burdens.
Paving the way for other non-invasive diagnostics: Success here could accelerate development of similar tools for other conditions that currently require surgery for diagnosis.

Background

Endometriosis has historically been underdiagnosed and under-researched. The gold-standard diagnostic method – laparoscopy – is invasive, expensive, and carries surgical risks. Many patients undergo years of misdiagnosis, often being told their pain is “normal” or psychological.

Over the past decade, research into biomarkers has intensified. MicroRNAs, cytokines, and other molecules have shown promise in small studies, but none has reached clinical practice. The UK trials mark the first time a saliva-based microRNA test and a gut-electrical test have been evaluated head-to-head in primary care.

The NICE approval for these trials reflects growing policy recognition of the need for faster diagnostics. Similar efforts are underway in the US and Europe, but the UK trial is the most advanced in terms of real-world implementation.

Key Perspectives

Patients and advocacy groups: They see the tests as a long-overdue breakthrough. Faster diagnosis means earlier access to pain management, fertility counselling, and treatments like hormonal therapy or surgery. Clinicians and researchers: They welcome the trials but stress that the evidence is preliminary. Sensitivity and specificity numbers from selected populations may not translate to general practice. A negative test could still miss endometriosis, while a positive one might pick up other conditions. Critics/Skeptics: Some worry about over-promising. The tests are not yet validated in diverse populations, and cost-effectiveness is unknown. There is also a risk that a “quick test” might encourage GPs to skip proper clinical assessment, leading to missed comorbidities or alternative diagnoses.

What to Watch

Interim results from the UK trials, expected within 12–18 months, showing how the tests perform in a real-world GP patient mix.
Cost and reimbursement decisions by NICE and other health technology assessment bodies, which will determine if these tests become widely available.
Regulatory approvals outside the UK – particularly in Australia and the US – which may follow if the trials succeed.

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