ID is not different than creationism, it just uses different terminology with some additional quasi-scientific obfuscation. Consider the creationist textbook, Of Pandas and People:

... a comparison of an early draft of Of Pandas and People to a later 1987 copy showed how in hundreds of instances the word "creationism" had been replaced by "intelligent design", and "creationist" simply replaced by "intelligent design proponent".

Can you think of any other 2 intellectual theories where you could take a book written about one and do a global search-and-replace on a few key terms in order to yield a good launching point for a book about the second theory?