i'm sure you'll get a better response but I am pretty sure it means people who get IBS after some sort of infection. Often people have a bout of gastric infection and then develop IBS. a lot of people can pinpoint when their IBS started. I can not - I certainly dont think mine is tied to any one specific event. I;'m also not sure that it makes a difference most of the time. Most people still have to figure out how to treat it. It can though help if something about the start is tied to triggers for you. I think finding out what triggers a problem is often the keynancy