Sudden onset in early 40s, shortly after probable low level food poisoning almost 3 years ago. All manner of existing conventional and complementary treatment has reduced the intensity of symptoms, of which I have many, but have not made them any more predictable or less chronic. I have been symptomatic every waking hour every day. I hope at some point well within my remaining lifetime, that will no longer be the case, but for now, I've pretty much been there and done that and don't expect it to subside any time soon.i was told by the doctor today it occurs mostly between 20 and 40 and normally subsides,if this is the case i thought it a relevant question to ask peoples ages here and when it started for you?