They likely won't make things worse but they likely won't help much with IBS. I have never meet anyone in a health food store that knew much about IBS. They are probably not the right people to ask for advice about IBS.
It is unlikely than many of us with IBS will ever be normal again. The best we can do at the moment is learn to manage the symptoms using diet, exercise and other things like hypno. So don't feel alone. There are millions of IBSers in the world with the same problem Some day medicine might have better solutions for us.
-------------------- STABLE: ♂, IBS-D 50+ years - Science of IBS