Google 'Shepherd et al' for information on those who developed it (in Australia), and for information on its aims etc. Here in the UK much work was undertaken by London hospitals: King's, St. Barts and St. Thomas'.
Fodmaps has been successfully used to identify which food(s) caused problems (fermenting in the gut) for some patients. Following identification the 'problem' foods were eliminated for a time, and then reintroduced.
Overall, the advice appears to be that it is not as simple as just eliminating some or a group of foods - the foods requiring elimination need to be identified.
I'd suggest a trip to your local library (if you are lucky still to have one!!!), and seek out some books giving advice on how to follow Fodmaps.
It may be even better if you could speak with a Dietitian who has experience in Fodmaps. Why not ask your GP to refer you? Correctly followed, Foodmaps has reportedly been highly successful for a number of patients.
Wishing you well.