Could have been all those banana lollies and an intolerance to sugar!
Seriously though, Elijah Craig is a pretty refined spirit, and I don't think there's anything in there that would have been the catalyst for your discomfort the next day. Could it possibly have been some food, or lack of sleep that contributed also?
I suspect a more likely explanation would be that, perhaps on this occasion, you neglected to drink water or re-hydrate yourself during or after the bourbon session. This can be particularly nasty if you were already somewhat dehydrated before starting the session.
(Happened to me once.....played squash all afternoon, sweated like a pig, and didn't drink nearly enough water afterwards. Then came home, had a few beers and some fairly decent drammage on the scotch front, and I was absolutely knackered the next morning).
I suppose a more scientific approach would be to repeat your evening, this time drinking heaps of water, and let us all know how you feel the next day.