A hydrogen breath test is commonly used to investigate bowel symptoms such as diarrhoea, bloating or abdominal discomfort. The results can help to identify the cause so that the most appropriate and effective treatment is recommended.
02036532009
A hydrogen breath test is a straightforward and non-invasive test that measures the levels of hydrogen and methane gases in your breath when you exhale.
Under normal circumstances, gases such as hydrogen and methane are produced by bacteria which live in the large bowel (colon) when they break down food. Gases are able to pass out of your gut into the bloodstream and circulate to the lungs, where they are exhaled in your breath. The amount of hydrogen and methane in a sample of your breath can be measured using a special monitor.
We can use the change in the amounts of these gases over time (after a sugary drink) to test for small intestinal bacterial overgrowth (SIBO) and carbohydrate malabsorption.
At Welbeck, this simple, non-invasive test is performed by our consultant gastroenterologists in our state-of-the-art Digestive Health centre.
Our breath tests are for anyone who experiences possible symptoms of small intestinal bacterial overgrowth (SIBO) and finds that at-home management has not helped. Breath tests can also be used to identify carbohydrate malabsorption.
Small intestinal bacterial overgrowth (SIBO) occurs when bacteria which are normally present in the colon have moved into the small bowel. This is where glucose is usually absorbed, but if bacteria have increased in that area, they will break down the glucose drink we give to you and produce hydrogen.
Bacterial overgrowth usually occurs because of abnormal movement of the gut. It’s most common in patients with illnesses which directly or indirectly affect the gut and less common in patients with no underlying illness or Irritable Bowel Syndrome.
Possible symptoms of SIBO include:
loss of appetite
diarrhoea
weight loss
stomach pain
nausea
bloating
indigestion
constipation
abdominal swelling
flatulence
feeling uncomfortably full after eating
malnutrition (in severe cases)
Carbohydrates (sugars) such as lactose and fructose are usually absorbed in the small bowel. If some of the sugar is not absorbed and reaches the large bowel, this is referred to as malabsorption. If sugar reaches the large bowel, the gut bacteria which live there break it down and produce gases such as methane and hydrogen, which we can measure using a breath test. Malabsorption of lactose or fructose can lead to symptoms such as cramping, bloating and diarrhoea, and this is called lactose or fructose intolerance.
Symptoms of intolerance can vary depending on the person and the amount of sugar they have eaten. An intolerance is not an allergy, and for most people, treatment involves being aware of the problem and lowering the dose of these sugars rather than complete avoidance.
If you’re unsure if breath testing is correct for you, don’t hesitate to contact us. Our team will happily discuss your symptoms and advise whether breath testing will benefit your wellbeing.
The first step of the test is to provide a fasting sample by holding your breath and then breathing out into a mouthpiece attached to a specialist device that measures the gases in your breath sample. This records the base levels of hydrogen and methane in your breath so that the results of further samples from the test can be compared.
Once the fasting sample has been collected, you’ll be given a sugar solution to drink (glucose, lactose, or fructose). You’ll then give multiple breath samples at approximately 15-minute intervals, over the course of 90 to 180 minutes (depending upon which test you are undertaking). You may be asked to record any symptoms over this time.
The test is simple and non-invasive, but it is time-consuming, so we recommend you bring something with you to read. You can also access our Wi-Fi network in our waiting areas if you wish.
There are no risks involved in having a breath test. If you’re intolerant of the sugar you’ve been given, the drink may reproduce your typical symptoms, but no harm can come from the test.
Some preparation is required ahead of taking a hydrogen breath test to ensure the results are as accurate as possible. You’ll be given full details by your specialist, but all patients must:
stop taking any antibiotics and probiotics 1 month before the test
eat a low-fibre diet the day before the test
fast (consume no food or drink, except small sips of water) for at least 12 hours before the test
The test is straightforward and non-invasive, so you can go home as soon as the test has been completed and can eat and drink normally straight after.
Please contact our Digestive Health centre for pricing.
At Welbeck, our digestive health specialists are experts in their field and are dedicated to providing world-class care to every patient.
With access to colleagues across other specialties, our consultants are also able to refer within the Welbeck ecosystem if needed to ensure you receive the treatment you need as quickly as possible, all under one roof.
All appointments, testing, treatment, and follow-up appointments take place within our state-of-the-art facilities, enabling us to deliver accurate diagnostics and advanced treatments.
At Welbeck, your safety and comfort are our priority, and we take every step to make the testing experience as smooth and reassuring as possible.
If you would like to schedule a consultation with a Welbeck specialist, please get in touch to make an appointment. Your health is important to us, so we strive to offer same-day appointments whenever possible.
Our consultants are recognised by the major health insurance companies. If you have private health insurance, your treatment at Welbeck can begin once you have obtained authorisation. We also provide care to self-paying patients. Learn more about the different payment options at Welbeck.
Results are usually available shortly after the test is complete, as the readings are taken in real time. Your consultant will review the data and explain what it means for your symptoms.
Some medications—such as antibiotics, probiotics, and laxatives—can interfere with the results, so it’s important to follow the preparation guidance you’re given. Always let your consultant know about any medicines you’re taking so they can advise you.
As the hydrogen breath test is non-invasive and does not involve sedation, you can attend and leave on your own. However, some people choose to bring a friend or family member for company, as the test can take a couple of hours.
Yes. If your symptoms change or further clarification is required, the test can be repeated safely. Your consultant will advise on the timing and whether another test would provide useful information.
Currently selected day
Available consultations
What is a hydrogen breath test?
What does a hydrogen breath test involve?
What are the risks of a hydrogen breath test?
How to prepare for a hydrogen breath test
Recovery and aftercare
How much does a private hydrogen breath test cost?
Why choose Welbeck?
Booking a private hydrogen breath test
FAQs