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We provide these tests in clinics around Australia, and also have send-out Home Test Kits available for customers in rural areas and around the world. In order to complete the testing, the patient needs to have very low bacterial activity in their digestive tract. The level of bacterial activity needs to be to as close as zero as possible. This can only be done by strictly following our pre- test diet for two full days prior to each test. The pre-test diet is designed to lower the bacterial activity by limiting FODMAP sugars that are known to cause the patients IBS-type symptoms- namely Fructose, Lactose and Sorbitol.

At the start of each of these breath tests, the patient must create a ‘baseline’ breath sample. This baseline breath sample will provide your ‘resting’ Hydrogen and Methane levels.

The patient will then consume a sugar drink. The amount of sugar that is given is based on the most up to date research in breath testing for accuracy of results without provoking unnecessary symptoms.

After the sugar drink, patients will create further breath samples at 20 minute intervals for the next 2 to 3 hours. If the sugar passes through the small bowel with minimal or no absorption through the gut wall, it will carry through into the large bowel. This is where the bacteria will begin feeding on the sugar.

The fermentation of the sugar by the bacteria converts it in part to a gaseous response. This response is able to be measured via your exhaled breath content in the form of hydrogen and methane. It is this increase in gases that indicate if the patient has a problem absorbing that particular sugar.

If the testing is done in the clinic, our clinic staff will administer the testing. If the testing is done at home, the patient post completed sample bags back to Stream Diagnostics. Both routes are highly accurate and reliable. Choosing between the two comes down to location and personal preference.



Patients cannot have had Colonoscopy, Enema, Colonic Irrigation Therapy, or Bowel Prep in the 4 weeks leading up to the testing.

Note: Gastroscopy and procedures that only require fasting are allowed in this time.


Patients must avoid Antibiotics and highly concentrated Probiotics in the 2 weeks leading up to the testing, and must refrain from taking for the duration of the testing.
Note: Probiotic yoghurts and fermented milk drinks are allowed in this time.


Patients must avoid Proton Pump Inhibitors (PPIs) for 1 week leading up to testing. Examples include Nexium, Pariet and Losec.


To provide the most accurate, usable result for their test, patients must follow a our LOW FODMAP diet for the two days prior to each test. The diet contains no fermentable sugars. This reduces the possibility of a ‘false positive’ in your results. The pre-test diet will be supplied to you when booking in for a test, or ordering a test kit.


FODMAPs are a collection of sugars (and related molecules) found in food that some people poorly absorb. FODMAPS include Fructose, Lactose, Sorbitol, Mannitol, FRUCTANS and GOS. When these sugars are poorly absorbed in the small bowel, FODMAPs continue their journey along the digestive tract and arrive at the large bowel. There the FODMAPS act as a food source to the bacteria that live normally in the large bowel. These bacteria digest the FODMAPs and trigger symptoms of Irritable Bowel Syndrome. Our Tests page gives information about each of the sugars we test for at Stream Diagnostics.


Stream Diagnostics only uses simultaneous Hydrogen and Methane breath analysers and most up to date research-based protocols for your tests. Our testing apparatuses and procedures are the most sensitive in this field. It is important to have breath tests measure both Methane and Hydrogen, as while most people produce a response via hydrogen output in their exhaled breath, a range of people may produce stronger responses via the methane in their exhaled breath. Some people produce both hydrogen and methane, and very small percentages produce very little to no hydrogen or methane in their expired breath.