I think it IS possible to determine IBS without all the invasive tests. Following the EFI and finding good results shows me that it most likely IS IBS. If you follow these guidelines and are still having some serious problems THEN you should consider looking at other problems.
Talking about your symptoms to your doctor and even to your family and friends can unleash a multitude of answers. you may find that your mom suffered from stomach issues or your grandparents did...even aunts and uncles, and in my case all of my family have similar issues.
For my family we have figured out that stress is what has caused our bowel and stomach issues.
No stress and we feel fine.
I haven't had all the tests Heather says we should have but have had a few others.Nothing serious has shown up and the doctors can't tell me what is wrong. My own research led me here and within a few weeks the EFI diet did for me what many doctors couldn't.
You need to educate yourself. Not focusing on th efact that you have IBS is the first step in getting it undercontrol.
You are not IBS you HAVE IBS.
That isn't to say that if you still have serious issues that you shouldn't see a doctor and have further testing done but I don't think you can say to anyone no you don't have IBS because you didn't do all these tests.
-------------------- IBS-D since 1999...mostly stable..i do cheat too.Bad me.