I believe that it is not only single food that triggers allergic reaction, but combination of two or more also triggers allergic reaction. Mono meals are a good idea. I know a few people had allergy to sesame seeds and it took years to figure it out. Especially when sesame was combined with sugar.
If you eat different foods with four hour in between you should be ok.
Yes, I agree with WS, Liver Flush is a good idea, I would refeed for at least twenty one days then do the flush.
I do Dr. Clark version of liver flush. The recipe is on CZ, you can search it.