I believe that colic and fussiness is almost ALWAYS caused by a food
sensitivity.  I have neever seen a baby that did not respond to a mom
eliminating the offending food(s) from her diet.  I do not encourage
blanket statements about what foods are the ones to eliminate though.  I
encourage them to figure it out using ideas laid out in the bf answer
book.

    I have four children and was able to completely erradicate fussiness
with each child ( ear infections and colds too).
My first child was sensitive to chocolate and milk products
My second it was peanut butter
My third it was eggs and milk
My fourth it was milk, chocolate, raw tomatoes, and soy

It all comes down to obeying your childs cues.

 I beleive that partly because of antibiotics food sensitivities are
more common than ever.
-Joyce Mitchell LLL leader in Provo Utah