As per the Wall Street Journal article, the IBS Self Help and Support Group has established a worldwide registry for dietitian's who are able to administer the low FODMAP diet.
I'll try and share the URL for the registry here, though I know that external URL's are not allowed here. If it has been edited out, you can find the registry on the IBS Self Help and Support Group website at the top of the Diet forum.
http://www.ibsgroup.org/forums/topic/155678-low-fodmap-diet-worldwide-dietitian-registry/
Jeffrey Roberts, Founder
IBS Self Help and Support Group
Post Edited (ibsgroup) : 8/1/2012 2:13:42 PM (GMT-6)