You can see in this chart just how common the problem is worldwide.
To mention just a few, 15-19% of New Zealander’s, 10-14% of British and 5-9% of Americans and Australians are affected.
It is interesting how less than 5% of Chinese and Indian people have IBS while Mexicans are over 30%. The obvious question raised here is, has this got something to do with local dietary habits?