i think Rach75 listed a good reference, i was going to google something like that and post it here if no one else had. the book 'fed up' by Sue Dengate is really good, it is probably worthwhile getting it and having a read. I have had major issues with my DS from probably around the same...actually probably a little earlier LOL. the main things that effect him are preservatives, flavours and colours. Colours are the HUGEST one for us. we're pretty sure hubby is anaphylactic to artifical colours, and if DS has anything with artificial colours in it, he goes absolutely cuckoo!!

i think something i have done is learning which brands do and don't have the bad stuff in them. Like Kraft peanut butter has the bad antioxidant 320 (which you should avoid) whereas the Aldi peanut butter has antioxidant 306 (which is safe.) don't use drinks which artificial that have added colours or flavours like cordial, etc...

it's just a matter of trial and error. you would be suprised how many products have stuff in them that you should avoid! but read some books, and just try and cut out as much of the food you can that has the artificial additives in them, and see if that makes a difference all the best!