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Gastroenterology · London

H. pylori breath test, urea breath test for diagnosis and post-treatment confirmation of Helicobacter pylori.

The urea breath test (UBT) is the gold-standard non-invasive test for Helicobacter pylori. Detects active infection and confirms eradication after triple / quadruple therapy - used for dyspepsia workup, peptic ulcer follow-up and MALT lymphoma.

A patient completing a ¹³C-urea breath test in a private London clinic

Key facts

What to know about the ¹³C-urea breath test.

A short brief for patients - what the test does, how it fits with the alternatives, and what it needs from you before you attend.

In short

A 30-minute non-invasive test - accurate for active infection and the standard test of cure after eradication.

Fact Detail
Definition ¹³C-urea breath test for Helicobacter pylori.
Test time Non-invasive, 30-minute test.
Medication wash-out Requires 2 weeks off PPI and 4 weeks off antibiotics.
Post-therapy use Confirms eradication after triple / quadruple therapy.
Complementary tests Complements stool antigen and endoscopic biopsy CLO.
Serology limitation Preferred over serology, which cannot distinguish past from active infection.

Preparation

From appointment to result - what happens, in order.

The medication wash-out is the part that catches people out - plan it in from the very first message.

  1. 01

    Before

    Referral or self-book

    A short, confidential form. Symptoms, prior eradication attempts, current medications.

  2. 02

    Before

    Stop PPI 2 weeks pre-test

    Proton-pump inhibitors suppress the urease reaction and cause false negatives - stop for at least 14 days.

  3. 03

    Before

    Stop antibiotics and bismuth 4 weeks

    Recent antibacterial exposure - including bismuth - must be washed out for a full 4 weeks.

  4. 04

    Before

    Fast for 6 hours

    No food or drink other than water for 6 hours before your appointment.

  5. 05

    On the day

    Drink the ¹³C-urea test solution

    A small drink of citric-acid solution containing ¹³C-labelled urea, taken in the clinic under supervision.

  6. 06

    On the day

    Breath samples at 0 and 30 minutes

    A baseline breath sample, then a repeat 30 minutes later - that is the whole test.

  7. 07

    After

    Result issued same day or next day

    Isotope-ratio mass spectrometry is fast - a written interpretation follows, with the onward gastroenterology pathway if needed.

Typical end-to-end from first appointment to report: 2–4 weeks, driven mostly by the PPI wash-out.

What it shows

When the H. pylori breath test is the right test.

The urea breath test answers a specific question - is H. pylori active in your stomach right now - and it does that better than any other non-invasive test.

  • Active H. pylori infection

    The gold-standard non-invasive test for current, active Helicobacter pylori.

  • Post-eradication test of cure

    The recommended way to confirm eradication after triple or quadruple therapy.

  • False positive with urease bacteria

    Other urease-producing organisms (uncommon) can lift the reading - interpret in context.

  • Repeat testing after failed eradication

    Guides second-line and salvage regimens when a first course has not worked.

  • Complements stool antigen

    Concordance with stool antigen or biopsy CLO strengthens the diagnostic picture.

  • Baseline before triple therapy

    Confirms infection before committing to a week of combination antibiotics and a PPI.

  • Screening high-risk populations

    Family history of gastric cancer, MALT lymphoma follow-up, or long-term NSAID users.

  • Red flag: dysphagia, weight loss, bleeding - endoscopy pathway

    Alarm features aren’t a breath-test question. Direct-access gastroscopy is the right route.

Next steps

If the test is positive - the treatment options.

What each pathway is actually for, from first-line therapy through to specialist referral.

  • First-line triple therapy

    PPI + amoxicillin + clarithromycin for 7 days - the standard first course in most UK patients.

  • Bismuth quadruple therapy

    PPI + bismuth + metronidazole + tetracycline - the preferred second-line regimen after first-line failure.

  • Levofloxacin-based regimen

    A third-line option after two prior treatment failures, guided by local resistance data.

  • Culture-guided therapy

    Endoscopic biopsy with culture and sensitivity for resistant or refractory infection.

  • Test of cure at 4 weeks

    Repeat breath test at least 4 weeks after therapy - earlier testing risks a false negative.

  • Gastroscopy if alarm features

    Upper GI endoscopy for dysphagia, weight loss, anaemia, bleeding or a palpable mass.

  • MALT lymphoma pathway

    H. pylori-associated gastric MALT lymphoma - eradication plus specialist haemato-oncology follow-up.

  • Structured gastroenterology follow-up

    Consultant review to close the loop on symptoms, eradication and any ongoing dyspepsia.

Red flags

When a breath test isn’t the right first step.

H. pylori breath testing is safe. The practical points are when endoscopy comes first, and where a positive result changes the whole pathway.

  • Alarm features (weight loss, dysphagia, anaemia, bleeding, mass)

    These aren’t a breath-test question. Direct-access gastroscopy is the right first step.

  • MALT lymphoma

    Eradication is part of the pathway, but haemato-oncology follow-up is essential.

  • Peptic ulcer with bleeding

    Acute upper GI bleeding is a hospital admission - 999 or A&E, not a private slot.

  • Family history of gastric cancer

    A lower threshold for endoscopy and surveillance, even with a negative breath test.

  • Post-eradication failure

    A positive test of cure means salvage therapy - and often endoscopic culture.

  • Multi-drug resistance

    Repeated eradication failures need culture-guided therapy from a specialist.

  • Recurrent NSAID use with ulcers

    H. pylori is only part of the story - NSAID review and gastroprotection matter.

  • Post-transplant patient

    Immunosuppression changes the risk profile; specialist input is essential.

  • Uncontrolled reflux with dyspepsia

    A negative H. pylori test does not close the loop - reflux workup may still be needed.

Reading your report

A urea breath test report is short. Four parts.

Whether the result is positive, negative or equivocal, the report keeps to the same four parts.

A consultant gastroenterologist reviewing a ¹³C-urea breath test result on a clinical workstation at a UK private clinic

A quiet reminder

The report is written for your doctor, not for you - and that’s normal.

If you would like us to talk you through it before your follow-up, just ask.

  1. 01 Header

    Indication and medication history

    Your details, the reason for testing, and confirmation of PPI and antibiotic wash-out.

  2. 02 Technique

    Protocol and baseline sampling

    The ¹³C-urea dose, sampling times, and the isotope-ratio method used to measure delta over baseline.

  3. 03 Findings

    Delta-over-baseline (DOB) value

    A numeric DOB value with the laboratory’s validated cut-off - positive, negative or equivocal.

  4. 04 Impression

    The conclusion: read this first

    Active infection, eradicated, or equivocal - and the concrete next step, read this first.

Recognised by major UK insurers

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Frequently asked

Everything we get asked about the H. pylori breath test.

Quick answers on wash-out, accuracy versus stool antigen and biopsy, referrals, and what happens if the test is positive.

  • What does the H. pylori breath test show?

    The urea breath test detects active Helicobacter pylori infection in the stomach. You drink a small amount of ¹³C-labelled urea; if H. pylori is present, its urease enzyme splits the urea and releases labelled carbon dioxide, which is measured in your breath 30 minutes later.

  • Why do I have to stop PPIs and antibiotics before the test?

    Proton-pump inhibitors and antibiotics suppress H. pylori and its urease activity, which produces false negatives. Guidance is 2 weeks off PPIs and 4 weeks off antibiotics (and bismuth) before testing - otherwise the result cannot be trusted.

  • How is the breath test used to confirm eradication?

    After a course of triple or quadruple therapy, a repeat breath test at least 4 weeks post-treatment is the recommended test of cure. Testing earlier risks a false negative because bacterial numbers can be temporarily suppressed.

  • How does the breath test compare to stool antigen and biopsy?

    Stool antigen and urea breath test have very similar accuracy for active infection. Endoscopic biopsy (CLO / histology / culture) is used when endoscopy is needed anyway - for alarm features, ulcers, or resistant infection. Serology cannot distinguish past from current infection and is generally not recommended.

  • Do I need a referral?

    Most clinics accept self-referral for a urea breath test.

  • What if my test is positive?

    A positive result usually leads to first-line triple therapy (PPI + amoxicillin + clarithromycin for 7 days), with a repeat breath test at least 4 weeks after finishing treatment to confirm eradication. Failed courses lead to bismuth quadruple therapy or culture-guided treatment.

Sources

The guidelines behind this page.

Reviewed by Pulse Atlas Editorial Board, . Published 2026-07-30. Next review 2027-07-30.

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In practice, in London

Booking helicobacter pylori breath test privately in London - what actually happens

With helicobacter pylori breath test, the London question is usually about report turnaround and the radiologist reading it - not whether the scan is available. The wait for helicobacter pylori breath test on the NHS depends heavily on where you live and how urgently the referral is graded. Central and West London private clinics can normally book within a week, with imaging or a procedure slot to follow shortly after. It’s worth being honest about the reason for going private: usually it’s time, not a fundamentally different test.

A private helicobacter pylori breath test pathway in London usually looks like this: an initial consultation, any diagnostics booked at a nearby facility (most within Zone 1 or 2), and a written report sent to you and your GP within a few days. The consultants we work with hold NHS posts alongside their private lists, which keeps the standards consistent across both settings. For helicobacter pylori breath test specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.

There are dozens of consultants in London who see helicobacter pylori breath test - but not all of them are the right fit for every case. The right first appointment saves you from repeating yourself later.