What is a hydrogen & methane breath test?
A hydrogen and methane breath test is used to detect abnormal growth of bacteria in the small intestine or small intestinal bacterial overgrowth (SIBO) which can cause a variety of symptoms including diarrhoea, nausea, bloating, gas and abdominal cramps.
The breath test detects hydrogen and methane, which are gases produced by intestinal bacteria. Bacteria normally found in the large intestine produce these gases through fermentation of carbohydrates/sugars. In SIBO, these bacteria move into the small intestine, meaning they break down the sugars before the body has had chance to digest them. This causes an over-production of gases such as hydrogen and methane.
These gases are absorbed into the bloodstream and transported to the lungs. They are then exhaled by the lungs and can be collected in breath samples for analysis.
Are there any risks associated with this test?
There are no risks involved in performing your test, you may experience some of your usual symptoms during the test, this is normal.
What preparation is required for your test?
Key
Do
Dont
Additional info
For 4 weeks before your test
Do not take any antibiotics.
For 1 week before your test
Do not take laxatives or stool softeners
Movicol, Dulcolax, Ex-Lax, Senna, Milk of Magnesia etc.
Do not take stool bulking agents
Metamucil, citrucel etc.
Do not take motility agents
Prucalopride, linaclotide etc.
Do not take probiotics
VSL#3, Actimel, Yakult etc.
You can continue taking any other essential medicines.
Additionally, there must be a period of one week between any tests which require cleansing of the bowel e.g. colonoscopy, barium enema, before having a breath test.
The day before your test
You must follow the ‘white food diet’ which consists of only the following foods and drinks:
- Plain white bread or plain white gluten free bread
- Plain white rice
- White potatoes (no skin)
- Baked/grilled chicken, turkey, lean beef, lean pork, white fish (no oily fish)
- Maximum of 2 eggs
- Water (non-carbonated)
- Non-flavoured black coffee (no milk)
- Non-flavoured black tea (no milk and no herbal teas)
- 1 tbsp butter/margarine/oil
- Salt to flavour food
Do not eat or drink anything else, eating prohibited foods could give false results
for the test.
We understand that this is a very bland diet and not everyone eats the food listed, but unfortunately any other foods may impact the results of the test. Patients that don’t like the foods listed can choose to fast for the full 24hrs before the test if they prefer.
For 12 hours before your test
You must stop eating and drinking and fast for 12 hours before your test.
On the day of your test
You can have small sips of water (maximum of 300 ml) until the start of your test.
You may take your essential medicines with a small amount of water but do not take anything that may affect your bowel (see previous list).
You may brush your teeth, but please try not to swallow any toothpaste.
Do not eat, drink, chew gum, smoke, eat breath mints and/or other sweets on the morning of or during of your test.
If you are diabetic requiring insulin or diabetes medicine, please ask your doctor
if you should change your morning dose. Oral hypoglycaemic medicines are usually not taken that morning until completion of the test and you start eating again.
How will I get my results?
Your results will be sent by secure email to both you and your referring consultant/doctor. We aim to send out all patient results within five working days of receipt of test by the lab.
