I think we are each very different with different bodies and different needs and we have to find our own journey/way to wellness! My body is constantly changing its needs...so much so I can hardly keep up!
For example, many people grow up with asthma and it gets better as they mature. OR the example of the person who has an intolerance to a food. They take it out of their diet for many many months and when they reintroduce it, that food is no longer a problem.
That is my experience...I am forever evolving and so are my nutritional needs.
I am also on medication and that factors in as well.
That being said...Heather's basic guidelines are FANTASTIC for IBS. But notice how she encourges the hypno tapes, alternative therapies, and getting to know our bodies better in her book and on the boards! She is an advocate of getting to know our bods better so we can feel better!
I think we should def. learn about things that are out there...it can't hurt! And no one thing will work for everyone all of the time. But I think Heather is DEFINATELY on to something with soluble fiber and avoiding trigger foods.
Do what makes sense to you and follow your soul...it will show you the way to go