SIBO Breath Testing in the UK

Medically reviewed and written by Dr Zeeshan Afzal, MBBS — Medical Content Lead, Welzo. Last reviewed: August 2026. Next review due: August 2027.

Persistent bloating that gets worse through the day, wind that arrives within an hour of eating, unpredictable bowels and a stomach that looks visibly distended by the evening — for a large number of people in the UK, these symptoms end with an irritable bowel syndrome (IBS) label and very little else. A SIBO test in the UK is one of the few investigations that attempts to look for a specific, treatable mechanism behind those symptoms: an excess of bacteria in the small intestine, detected by measuring hydrogen and methane in your breath.

This guide explains exactly how SIBO breath testing works, whether you can get one on the NHS, what private testing costs, how to prepare properly, and — critically — how to interpret the numbers on your report without over-reading them. If you are still at the "what is this?" stage, start with our overview of SIBO in the UK and our foundational guide to gut health in the UK. For products, browse the full Welzo gut health range and our clinically formulated probiotics collection. Readers investigating bacterial balance often also look at Akkermansia muciniphila, Welzo Ultra Purity Berberine, Citrus Pectin Powder and Welzo Ultra Purity TUDCA. Related reading: best supplements for IBS, IBS types, best supplements for bloating, the low FODMAP diet in the UK and gut microbiome testing.

This article is for information only. It is not a substitute for a diagnosis or a personalised treatment plan from your GP, gastroenterologist or pharmacist. If you have new, severe or changing bowel symptoms, see a doctor.

Table of contents

• What is SIBO?
• How a SIBO breath test actually works
• Can you get a SIBO test on the NHS?
• Types of SIBO test available in the UK
• How much does a SIBO test cost in the UK?
• How to prepare for a SIBO breath test
• What happens during the test
• How to read your SIBO test results
• Accuracy, false positives and false negatives
• What to do if your test is positive
• What to do if your test is negative
• Red flags: when to see a GP instead of testing
• How to choose a SIBO test provider in the UK
• Frequently asked questions
• References

What is SIBO?

Small intestinal bacterial overgrowth (SIBO) describes an excessive number of bacteria in the small intestine — the long, narrow section of bowel between the stomach and the colon where most nutrient absorption happens. The colon is meant to be densely populated with microbes. The small intestine is not. When bacteria migrate upwards or fail to be cleared, they ferment carbohydrates before you can absorb them, producing gas, osmotic fluid shifts and the symptoms that follow.

Image: Human digestive system. Illustration by LadyofHats, released into the public domain via Wikimedia Commons.

Why bacteria normally stay out of the small bowel

The body has several overlapping defences: stomach acid sterilises much of what you swallow, bile and pancreatic enzymes are antimicrobial, the ileocaecal valve acts as a one-way gate, and the migrating motor complex (MMC) — a wave of cleansing contractions that sweeps the small bowel between meals — physically flushes residual bacteria downstream. When any of these fail, overgrowth becomes possible. That is why low stomach acid, long-term omeprazole and other PPIs, gastroparesis, previous abdominal surgery, adhesions, diabetes and Crohn's disease all appear repeatedly on the risk list.

Typical symptoms

• Bloating and visible abdominal distension, often worsening through the day
• Excessive wind and belching (see trapped wind relief)
• Diarrhoea, constipation, or alternating patterns — track yours against the Bristol Stool Chart
• Abdominal pain or cramping shortly after eating
• Food reactions that seem to broaden over time, especially to fibre and fermentable carbohydrates
• In more advanced cases, nutrient deficiencies (particularly vitamin B12, iron and fat-soluble vitamins) and unintentional weight loss

None of these are specific to SIBO. They overlap almost completely with IBS, gut dysbiosis, candida overgrowth, coeliac disease and gluten intolerance, bile acid malabsorption and histamine intolerance. That overlap is precisely why testing — and interpreting the test properly — matters.

How a SIBO breath test actually works

Human cells do not produce hydrogen or methane. Every molecule of these gases in your breath originates from microbial fermentation in your gut. When gut bacteria ferment a test sugar, the gases they produce diffuse across the intestinal wall into the bloodstream, travel to the lungs and are exhaled. Measuring them in parts per million (ppm) over time therefore gives an indirect readout of where and how vigorously fermentation is happening.

You drink a measured dose of a test sugar, then provide breath samples at fixed intervals — typically every 15 to 20 minutes for two to three hours. A rapid early rise suggests fermentation is happening high up, in the small bowel, before the sugar reaches the colon. A late rise is usually just normal colonic fermentation.

Hydrogen, methane and hydrogen sulphide

Modern testing recognises more than one gas phenotype:

• Hydrogen (H₂) — produced by fermenting bacteria; the classic marker, more often associated with diarrhoea-predominant symptoms.
• Methane (CH₄) — produced not by bacteria but by archaea, principally Methanobrevibacter smithii, which consume hydrogen. Because this now reflects organisms outside the bacterial kingdom, the American College of Gastroenterology reclassified it as intestinal methanogen overgrowth (IMO) rather than SIBO. Methane is strongly linked with slowed transit and constipation. In one prospective cohort of 247 IBS patients, methane levels were significantly higher in constipation-predominant patients while hydrogen levels were higher in the diarrhoea phenotype.¹³
• Hydrogen sulphide (H₂S) — a third gas that also consumes hydrogen. It is measured only by a minority of three-gas panels and is not part of mainstream guideline thresholds yet.

This matters practically: a hydrogen-only test can return a false negative in someone whose overgrowth is methane-dominant, because the methanogens are consuming the hydrogen before it ever reaches your lungs. Any UK SIBO test worth paying for should measure hydrogen and methane as a minimum.

Glucose or lactulose — which substrate?

The two substrates behave very differently, and this single choice explains much of the disagreement about SIBO test reliability.

The sensitivity and specificity figures above come from a systematic review with meta-analysis comparing breath testing against jejunal aspirate culture, summarised in Clinical Gastroenterology and Hepatology.⁶ Neither test is close to perfect. Glucose is the more specific option — a positive result is more likely to be a true positive — which is why several specialist reviews argue glucose should be preferred when SIBO is genuinely suspected.⁹

Image: Chemical structure of lactulose. Public domain via Wikimedia Commons.

Can you get a SIBO test on the NHS?

Sometimes — but it is inconsistent, and you should understand why before you ask.

SIBO breath testing is not part of the routine NHS diagnostic pathway for IBS. The 2021 British Society of Gastroenterology guidelines on the management of irritable bowel syndrome do not endorse routine breath testing for SIBO in people presenting with IBS symptoms.⁴ Some NHS commissioning guidance is blunter still: one integrated care board pathway states that breath tests for SIBO have poor sensitivity and specificity, are not recommended in BSG guidance, have very limited NHS availability, and are prone to both false positives and false negatives — partly because the tests were originally designed to measure oro-caecal transit time, which is often abnormal in IBS anyway.⁷

Meanwhile, the American College of Gastroenterology does suggest glucose or lactulose breath testing for suspected SIBO in symptomatic patients — but every one of those diagnostic recommendations is graded as conditional and based on very low quality evidence.² A joint clinical practice update from the European Society of Neurogastroenterology and Motility and the American Neurogastroenterology and Motility Society has since critically appraised the SIBO hypothesis and breath testing as a whole.⁵

The honest summary: this is a genuinely contested area of gastroenterology, not a settled one. UK specialists tend to be more sceptical than US specialists. That does not make the test worthless — it makes the interpretation, and the clinical context around it, everything.

Practical NHS routes

• Your GP cannot usually order a SIBO breath test directly; it requires a gastroenterology referral.
• Some NHS trusts run hydrogen breath testing for lactose or fructose malabsorption but not a full SIBO protocol.
• Availability varies by region, and waiting lists can be long.
• Your GP will normally first exclude the things that actually change management: coeliac serology, full blood count, inflammatory markers, and faecal calprotectin. Those are the right first steps — see our guides to coeliac testing, calprotectin testing and gut health blood tests.

Going private

Most UK patients who get a SIBO test do so privately, either through a private gastroenterologist, a specialist clinic, or a postal at-home kit analysed by an accredited laboratory. A private test is reasonable if you have persistent, well-characterised symptoms and you intend to act on the result with clinical support. It is a poor idea if you are testing out of anxiety, plan to self-treat with antimicrobials, or have red flag symptoms that need urgent assessment instead.

Types of SIBO test available in the UK

How much does a SIBO test cost in the UK?

Prices move, so treat these as indicative ranges rather than quotes. Always check what is actually included before you buy.

A cheap test with a hydrogen-only readout, a two-hour window, and no interpretation is usually false economy. You are paying for the interpretation as much as the gases.

How to prepare for a SIBO breath test

Preparation is not optional detail — it is the single biggest determinant of whether your result means anything. Poor prep is the leading cause of uninterpretable and falsely positive tests.

Four weeks before

• No antibiotics. Specialist guidance advises avoiding antibiotics for four weeks before breath testing, since the test measures the by-products of bacterial fermentation.⁶ If you have recently finished a course, see probiotics after antibiotics and postpone your test.

Two weeks before

• No colonoscopy or other procedure requiring bowel prep.⁶
• Follow your provider's guidance on laxatives, prokinetics and stool softeners.
• Many labs ask you to pause probiotics; check your specific kit instructions and see when to take probiotics.

24 hours before: the prep diet

The aim is to empty the gut of fermentable substrate so that the only thing being fermented on test day is the sugar you drink. Typical instructions permit plain, low-residue foods and exclude fermentable carbohydrates entirely.

On the day

• Fast for 8–12 hours; water only.
• Brush your teeth and rinse your mouth before the baseline sample — oral bacteria acting on the test sugar can generate a misleading early hydrogen peak.¹⁴
• Do not smoke or vape before or during the test.
• Avoid exercise during the test — hyperventilation dilutes breath gases and can artificially lower readings.
• Stay seated and calm; sleeping during the test can also alter readings.
• Log your symptoms at each time point. A rise in gas that coincides with your typical bloating is far more clinically meaningful than a rise on its own.

What happens during the test

1. You provide one or more baseline breath samples after your overnight fast. An elevated fasting reading is itself informative.
2. You drink the substrate — 75 g glucose or 10 g lactulose, per North American Consensus doses.¹
3. You provide breath samples every 15–20 minutes for two to three hours, exhaling fully into a bag, tube or syringe device.
4. Samples are analysed by gas chromatography, either on site or after posting to the laboratory.
5. You receive a report plotting hydrogen and methane in ppm against time.

The procedure itself is painless and non-invasive. The commonest side effects are the symptoms the test is designed to provoke: bloating, wind, cramping and occasionally loose stools afterwards. That is expected — and worth recording.

Image: Digestive system. Blausen Medical Communications, Inc., CC BY 3.0, via Wikimedia Commons.

How to read your SIBO test results

Two consensus documents dominate interpretation worldwide: the 2017 North American Consensus and the 2022 European guideline produced jointly by EAGEN, ESNM and ESPGHAN.^1,3

The North American Consensus explicitly recommends using a rise of ≥20 ppm in hydrogen and states that the old "double peak" pattern should not be used to diagnose SIBO.¹ If your report leans on double peaks, it is using outdated criteria.

Hydrogen-dominant results

An early hydrogen rise with matching symptoms suggests fermentation happening too high in the bowel. This pattern skews towards looser stools, urgency and post-meal bloating. Related reading: short-chain fatty acids and foods that cause bloating.

Methane-positive results (IMO)

Methane ≥10 ppm indicates methanogenic archaea. Because methane slows intestinal transit, this pattern maps onto constipation-predominant symptoms. It also tends to be more persistent and harder to shift than hydrogen-dominant overgrowth. See constipation relief and magnesium for constipation.

Negative or flat results

A flat trace does not automatically mean "nothing is wrong". It may mean you are a non-producer of both gases, that hydrogen sulphide is the dominant gas and was not measured, that your prep suppressed fermentation, or simply that your symptoms have a different mechanism — such as visceral hypersensitivity, bile acid malabsorption, or a gut–brain axis driver.

Image: Bristol Stool Chart, Cabot Health, CC BY-SA 3.0, via Wikimedia Commons.

Accuracy, false positives and false negatives

You should go into a SIBO test knowing its limits. Against jejunal aspirate culture, pooled figures put lactulose breath testing at roughly 42% sensitivity and 71% specificity, and glucose breath testing at roughly 55% sensitivity and 83% specificity.⁶ In plain terms: a substantial proportion of true cases are missed, and a meaningful proportion of positives are not real.

Why false positives happen

• Fast transit. If lactulose reaches your colon in under 90 minutes — common in diarrhoea-predominant IBS — the resulting hydrogen rise looks identical to small bowel fermentation but is entirely normal colonic activity.
• Inadequate prep. Residual fermentable food produces gas independent of the substrate.
• Oral bacteria. Skipping the mouth rinse can create a spurious early peak.¹⁴
• Substrate dose. UK data from 725 patients showed that moving to consensus doses changed positivity substantially: 10 g lactulose reduced positive results versus 16 g (42% vs 53%), while 75 g glucose increased positives versus 50 g (36% vs 22%).⁸ The same person can be positive on one protocol and negative on another.

Why false negatives happen

• Hydrogen-only testing missing methane-dominant overgrowth
• Hydrogen sulphide dominance on a two-gas panel
• Glucose being absorbed before it reaches distal overgrowth
• Recent antibiotics, or an over-restrictive prep diet, temporarily suppressing fermentation

How to use an imperfect test well

Treat the breath test as one input, not a verdict. A result is most useful when the symptom pattern fits, the gas phenotype matches the bowel habit, the prep was done properly, and a clinician is interpreting it alongside coeliac screening, calprotectin and bloods. A positive test in someone with no symptoms means very little. A negative test in someone with classic symptoms does not close the case.

What to do if your test is positive

Do not self-prescribe antibiotics or herbal antimicrobials. Take the result to a GP, gastroenterologist or registered dietitian who can put it in context.

Medical treatment

Guidelines suggest antibiotics in symptomatic patients with confirmed SIBO to eradicate overgrowth and resolve symptoms — again as a conditional recommendation based on low quality evidence.² Rifaximin is the most studied agent internationally; in the UK its licensing and availability for this indication are limited, and prescribing decisions belong with your clinician. Methane-positive cases are typically harder to treat than hydrogen-dominant ones.

Diet

Short-term reduction of fermentable carbohydrates can reduce symptom burden while other steps take effect. The evidence-based framework here is the low FODMAP diet, which should be time-limited and ideally dietitian-supervised — see our guides to the low FODMAP diet in the UK, the FODMAP food list and, crucially, FODMAP reintroduction. Long-term restriction is not the goal: it reduces microbiome diversity, which carries its own costs.

Addressing the underlying cause

Eradication without addressing the mechanism invites relapse. Recurrence after successful treatment is well recognised, and impaired migrating motor complex function is a leading explanation. Consider whether motility, medication (particularly long-term acid suppression), anatomy, or a systemic condition is driving the overgrowth. Our articles on the vagus nerve and gut motility and gut barrier function cover the physiology in more depth.

Supportive supplementation

Supplements do not eradicate SIBO and should never replace medical assessment. Some people use them supportively alongside a clinician-led plan, and several are commonly discussed in this context:

• Berberine — a plant alkaloid frequently discussed in gut-related protocols; note the potential for berberine interactions with prescription medicines.
• Citrus pectin — a soluble fibre; see modified citrus pectin vs pectin.
• Akkermansia muciniphila — a mucin-associated species; see Akkermansia vs probiotics.
• TUDCA — a bile acid derivative; review TUDCA side effects first.
• Enteric-coated peppermint oil — has the strongest evidence base of any over-the-counter option for IBS-type abdominal pain.
• Saccharomyces boulardii and spore-based probiotics — sometimes chosen where conventional strains aggravate symptoms. Whether probiotics help or worsen SIBO is genuinely unsettled; introduce slowly and see probiotic side effects.

Browse the full gut health collection and probiotics range, and speak to a pharmacist or doctor before starting anything if you take prescription medication, are pregnant or breastfeeding.

What to do if your test is negative

A negative SIBO test is genuinely useful information — it redirects the search. Consider whether your symptoms fit better with:

• IBS subtypes and visceral hypersensitivity
• Bile acid malabsorption, which is frequently mislabelled as IBS-D
• Lactose intolerance or fructose malabsorption — both testable with the same breath technology
• Coeliac disease versus gluten intolerance
• H. pylori, gastritis or acid reflux
• Inflammatory bowel disease — flagged by a raised calprotectin
• Dietary and lifestyle drivers, including ultra-processed food intake, sweeteners, shift work and stress

Rebuilding rather than restricting is usually the more productive long-term direction: see 30 plants a week, how to increase fibre and best foods for gut health.

Red flags: when to see a GP instead of testing

Book an urgent GP appointment rather than ordering a test if you have any of the following:

• Blood in your stool, or black tarry stools
• Unintentional weight loss
• A persistent change in bowel habit lasting three weeks or more, particularly if you are over 50
• A lump or mass in your abdomen
• Iron deficiency anaemia
• Difficulty swallowing, persistent vomiting, or waking at night with pain
• A family history of bowel cancer, coeliac disease or inflammatory bowel disease

Further reading: when to see a GP about stomach symptoms and bowel cancer screening in the UK. A private breath test is never an appropriate substitute for investigating red flag symptoms.

How to choose a SIBO test provider in the UK

Checklist before you buy

• Does it measure both hydrogen and methane? Hydrogen-only tests miss IMO entirely.
• Does it use consensus substrate doses — 10 g lactulose or 75 g glucose?¹
• Is the sampling window at least two hours, and three hours for lactulose?
• Are samples analysed by an accredited laboratory (UKAS, or an equivalent recognised standard)?
• Are the reference thresholds stated on the report, and do they match current consensus?
• Is clinical interpretation included, or are you buying a graph with no context?
• Is the prep protocol detailed and specific, or vague?
• Is there a clear pathway if the result is positive — or does the provider simply sell you their own protocol?

Questions worth asking your clinician

• Given my symptoms, will this result actually change what we do?
• Should we exclude coeliac disease and check calprotectin first?
• Could my current medications — PPIs, opioids, anticholinergics — be contributing?
• If I test positive, what is the plan, and how will we prevent recurrence?

Key takeaways

• A SIBO test in the UK is almost always a hydrogen and methane breath test using glucose or lactulose.
• Consensus thresholds: hydrogen rise ≥20 ppm within 90 minutes; methane ≥10 ppm at any point.
• Methane positivity is reclassified as intestinal methanogen overgrowth (IMO) and links to constipation.
• NHS access is inconsistent and UK guidelines are notably more sceptical than US ones; most people test privately.
• Sensitivity and specificity are modest — glucose is more specific, lactulose more prone to false positives.
• Preparation determines result quality more than any other single factor.
• Interpret results with a clinician, alongside coeliac screening, calprotectin and bloods — and never in place of investigating red flag symptoms.

Frequently asked questions

How much does a SIBO test cost in the UK?

Private at-home hydrogen and methane breath tests generally cost around £130–£220, with three-gas tests including hydrogen sulphide typically £200–£350. NHS testing is free at the point of use where it is available, but access is limited and requires a gastroenterology referral.

Can I get a SIBO test on the NHS?

Sometimes, via specialist referral, but it is not part of the routine NHS pathway. UK guidance is cautious: BSG IBS guidelines do not endorse routine SIBO breath testing, and some NHS commissioning pathways describe the tests as having poor sensitivity and specificity with very limited availability. Most UK patients test privately.

Is a SIBO breath test accurate?

It is useful but imperfect. Compared against jejunal aspirate culture, pooled estimates put glucose breath testing at roughly 55% sensitivity and 83% specificity, and lactulose breath testing at roughly 42% sensitivity and 71% specificity. Results should always be interpreted alongside your symptoms and other investigations.

Should I choose glucose or lactulose?

Glucose is the more specific substrate and produces fewer false positives, but it is absorbed early and can miss overgrowth further down the small bowel. Lactulose covers more of the small intestine but frequently reflects normal colonic arrival rather than true overgrowth. Many UK clinicians favour glucose when SIBO is specifically suspected.

How long does a SIBO test take?

Typically two hours for a glucose test and two to three hours for lactulose, with breath samples every 15 to 20 minutes. Postal kit results usually come back within a few working days of the laboratory receiving your samples.

What should I eat the day before a SIBO test?

Follow your provider's specific instructions. Prep diets generally allow plain protein, white rice, clear broth and water, while excluding all fruit, vegetables, pulses, wholegrains, dairy, fermented foods, fibre supplements, sweeteners and alcohol — followed by an 8–12 hour fast.

Do I have to stop probiotics before a SIBO test?

Most laboratories ask you to pause probiotics before testing, though the required window varies by provider. Antibiotics are the firmer rule: specialist guidance advises avoiding them for four weeks beforehand, and avoiding bowel prep procedures such as colonoscopy for at least two weeks.

What does a methane-positive result mean?

Methane of 10 ppm or more at any point indicates overgrowth of methane-producing archaea, now termed intestinal methanogen overgrowth (IMO) rather than SIBO. Because methane slows gut transit, it is associated with constipation-predominant symptoms and tends to be more stubborn to treat than hydrogen-dominant overgrowth.

Can a stool test diagnose SIBO?

No. Stool tests sample the colon, whereas SIBO is a small intestinal problem — the wrong compartment entirely. Stool and microbiome tests can be informative for other questions, but they cannot confirm or exclude SIBO.

Can SIBO come back after treatment?

Yes, and recurrence is common. Relapse is generally attributed to the underlying cause remaining unaddressed — most often impaired migrating motor complex function, but also anatomical factors, long-term acid suppression and post-surgical changes. Sustained improvement usually depends on treating the mechanism, not just the bacteria.

References

1. Rezaie A, Buresi M, Lembo A, et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. Am J Gastroenterol. 2017;112(5):775–784. Read the consensus
2. Pimentel M, Saad RJ, Long MD, Rao SSC. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. Am J Gastroenterol. 2020;115(2):165–178. View on PubMed
3. Hammer HF, Fox MR, Keller J, et al. European guideline on indications, performance and clinical impact of hydrogen and methane breath tests (EAGEN, ESNM and ESPGHAN consensus). United European Gastroenterol J. 2022;10(1):15–40. Read the guideline
4. Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021;70(7):1214–1240. View on PubMed
5. Kashyap P, et al. Critical appraisal of the SIBO hypothesis and breath testing: a clinical practice update endorsed by ESNM and ANMS. Neurogastroenterol Motil. 2024. Read the update
6. Small Intestinal Bacterial Overgrowth Breath Testing in Gastroenterology: Clinical Utility and Pitfalls. Clin Gastroenterol Hepatol. 2022. Read the review
7. Remedy BNSSG ICB (NHS). Small Intestinal Bacterial Overgrowth (SIBO) — clinical pathway. View the NHS pathway
8. Pitcher CK, Farmer AD, Haworth JJ, et al. Performance and Interpretation of Hydrogen and Methane Breath Testing: Impact of North American Consensus Guidelines. Dig Dis Sci. 2022. Read the study
9. Small Intestinal Bacterial Overgrowth Syndrome: A Guide for the Appropriate Use of Breath Testing. Dig Dis Sci. 2021;66(2):338–347. View on PubMed
10. Quigley EMM, Murray JA, Pimentel M. AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review. Gastroenterology. 2020;159(4):1526–1532. View on PubMed
11. Merck Manual Professional Edition. Small Intestinal Bacterial Overgrowth (SIBO). Read the entry
12. Cleveland Clinic. Hydrogen Breath Test: What It Is, How To Prep & Results. Read the guide
13. Prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome: correlating H₂ or CH₄ production with severity of IBS. Read the study
14. Ghoshal UC. How to Interpret Hydrogen Breath Tests. J Neurogastroenterol Motil. 2011;17(3):312–317. Read the article
15. NHS. Irritable bowel syndrome (IBS). Visit NHS.uk
16. NICE. Irritable bowel syndrome in adults: diagnosis and management (CG61). View NICE guidance

About the author

Dr Zeeshan Afzal, MBBS is a UK-registered medical doctor and Medical Content Lead at Welzo. He writes and reviews Welzo's clinical content, with a focus on digestive health, preventative medicine and translating specialist guidelines into practical guidance for patients. All Welzo health content is written or reviewed against current UK and international clinical guidance and updated at least annually.

Medical disclaimer

This article is intended for general information and education. It does not constitute medical advice, diagnosis or treatment, and it does not replace consultation with a qualified healthcare professional. Do not start, stop or change any prescribed medication based on this content. Supplements are not medicines and are not intended to diagnose, treat, cure or prevent any disease. If you are pregnant, breastfeeding, taking prescription medication or living with a diagnosed medical condition, speak to your GP or pharmacist before taking any supplement. If you have red flag symptoms such as rectal bleeding, unexplained weight loss or a persistent change in bowel habit, contact your GP promptly. In an emergency, call 999 or go to your nearest A&E.