People need to be careful about this.
There is a lot of evidence to suggest the IgG Antibody testing (used by YorkTest amoung others) cannot actually show food intolerance's.
The UK Advertising Watchdog took YorkTest to take in 2007 for the claims they were making.
The Australian Authority also cast doubt
An inquiry of the House of Lords in England also concluded there was no scientific basis to the tests.
I found some good blogs on this too:
Myth: You Can Diagnose Food Intolerance or Allergy with an IgG Blood Test
IgG Tests Are A Waste of Money: House of Lords Committee Hears Evidence, Let's Hope That They Listen
Its probably a good idea to read through the evidence that currently exists before deciding to spend €250+ on a test.