How can I check which FODMAP I cannot tolerate?
It is possible to test your ability to absorb certain carbohydrates using a breath test to check the levels of hydrogen and methane on your breath. This involves eating a low FODMAP and low-fibre diet the day before, as well as fasting overnight. At the start of the test, the baseline breath sample will be taken. You will then be given a carbohydrate to eat (e.g. fructose) and regular breath samples will be taken to measure the levels of hydrogen and methane on your breath. If the levels of hydrogen and methane are high, this indicates that the carbohydrate is not being absorbed. This test can be used to check your ability to absorb other carbohydrates.