Testing
SIBO breath testing
Small intestinal bacterial overgrowth is a real cause of bloating and altered bowel habit, and an over-diagnosed one. The breath test is the best non-invasive way to look for it, provided it is ordered for the right reasons and read alongside everything else.
At a glance
Greenland Medical offers private SIBO breath testing in Twickenham, London, and across the UK. Dr Andrew Greenland orders the Genova Diagnostics 3-hour lactulose breath test, measuring hydrogen and methane, which you do at home, and interprets it alongside your history and usually a stool analysis.
- Test
- Genova Diagnostics 3-hour SIBO breath test: lactulose, hydrogen and methane, eight samples
- Where
- At home, anywhere in the UK, with return shipping to the laboratory included
- Price
- £231, the laboratory’s price in October 2026. Laboratories change their prices, so I confirm the current figure before ordering
- Before and after
- Ordered after a consultation (functional medicine initial consultation £880), with a follow-up (£440) to go through the result and agree a treatment plan
- Often paired with
- A comprehensive stool analysis, covering the upper and lower gut together
- Treatment options
- Botanical or pharmaceutical antimicrobials, chosen with you and guided by laboratory sensitivity testing where an organism is cultured, plus diet and the underlying cause
- First appointment
- Usually within two to three weeks
Who it is for
People whose symptoms fit: bloating that builds after meals, wind, discomfort, and diarrhoea, constipation or both, particularly with a history of long-term acid suppression, previous abdominal surgery, slow gut movement, or IBS that has not responded to the usual approaches.
It is not a screening test, and I do not order it for everyone with a digestive complaint. Symptoms such as bleeding, weight loss or difficulty swallowing need NHS investigation first.
How the result is used
A rise in hydrogen suggests bacterial overgrowth; raised methane points to a different group of organisms and tends to go with constipation. Lactulose can produce false positives when the gut moves quickly, so the result is one piece of evidence rather than a verdict.
Treatment, where it is needed, is a choice made with you. Both botanical and pharmaceutical antimicrobials are options, and where a botanical option is suitable I usually consider it first. Addressing why the overgrowth happened matters as much as clearing it, because recurrence is common otherwise.
The full account, including preparation and the evidence for each treatment, is in the SIBO guide.
Common questions
Where can I get a private SIBO breath test in London?
Greenland Medical in Twickenham offers the Genova Diagnostics 3-hour lactulose breath test, done at home and available across the UK, for £231 including return to the laboratory (October 2026 price). It is ordered and interpreted by Dr Andrew Greenland, a GMC-registered doctor, as part of a consultation.
Can I just order the test without a consultation?
No. I see you first, so that the right tests are chosen and anything that needs NHS investigation is not missed, and then at a follow-up to go through the result and agree a plan.
Does the test measure methane as well as hydrogen?
Yes. Both are measured over three hours. Methane-dominant results are treated differently, which is why measuring both matters.
Related
Discuss your case with Dr Greenland
A short discovery call is the usual starting point. It costs nothing, and it is the fastest way to find out whether this approach fits your situation.