Diagnosis can be made 3 ways –
1. Hydrogen breath test
2. Stool test
3. Self-diagnosis. Keep a food diary of everything you’ve consumed and then how you feel after. Keep a note of the different symptoms and when they occur. The journal is important, as the effects of some foods can take hours or even up to 3 days to present.
Note: the breath test can return a false negative meaning it isn’t 100% reliable. Your body will tell if you if something’s wrong.