Michelle,
I am also desperately sensitive to caffeine and have drank ...2 or 3 sips of coffee in my life? That was enough.
Anyway, I have personally done a few coffee enemas and as my research told me - the caffeine is not absorped through the large intestine and so has no effect. I found the enemas to be beneficial. So I would put your caffeine reservations aside. The coffee has a completely different effect when put in the other way round :p
Floyd