Lactose Malabsorption Test



Lactose Malabsorption occurs when there is an inability to fully digest the ‘milk sugar’. Symptoms can begin soon after eating or drinking lactose containing food or drinks.

Lactose consists of two sugar units. An enzyme called lactase is required to split the lactose sugar into two single units for absorption. If you do not have enough lactase enzyme, lactose cannot be broken down and travels to the large intestine where it is digested by bacteria in your colon. The products produced by this process can cause symptoms such as diarrhoea, gas, bloating, nausea, vomiting, upset stomach, or flatulence.

The Hydrogen and Methane breath test is used to detect lactose malabsorption. This is a non-invasive investigation. You will be asked to perform a baseline breath sample by blowing into the analyser. Following this, you are given a lactose testing solution to drink. You will then be called into the clinic room at regular intervals to perform breath samples. If lactose is not absorbed, it travels to the large intestine. In the large intestine, the bacteria will break up the lactose and gases such as hydrogen, methane and carbon dioxide are produced. Hydrogen and methane have a small molecular size which means that they pass easily through the wall of the intestine and into the blood stream. When your blood circulates around your body to your lungs, these gases diffuse out of the bloodstream and are measured in your breath samples.

Please note that if you are on a long term antibiotic prescription, please contact us for testing advice. A pre-procedure instruction sheet can be viewed by clicking the download button below. This should be viewed and adhered to upon booking your appointment to ensure accurate results.

A copy of your results will be forwarded to your G.P/Consultant. In the event of a positive Hydrogen & Methane Breath Test, it is recommended that you see your G.P/Consultant for appropriate treatment.

This test can be performed at one of the clinics and results are available on the day of testing. Lactose malabsorption kits can be purchased from the online product store if you are unable to attend one of the clinics.


Test Duration: Up to 3 hours

Testing Age: Adults & Children over 25kg in weight

Referral: No referral required

Results: Available on day for clinic investigations

Clinic Test Fee: €140