We're another lot who have done elimination diets. You could get lucky with 2 weeks, you might not though.

We took out each group one at a time with our dietitian. Our first group was wheat (through known positive SPT) the results of that were noticable in days, but we had to stay off it for weeks before we could challenge it. The results were very convincing. We also went through fruit (it came under a special heading that I cant remember for the life of me) so not all fruit but particular ones, dairy, soy, wheat... some others too Im sure. We now live wheat, all nuts & soy free and allow small amounts of well cooked egg in there. Through being diligent and persistant my son is almost unmedicated now.