I don't think that was what that meant. I think the "throw up" part was in reference to the administering of the enema itself.
I don't believe that is what "throw up a clyster" means. If you google it, that particular phrasing is not uncommon to this story.
To me, from context (I have no special knowledge), "throw up a clyster" means to mix a clyster, not regurgitate it.
I'm guess its like knocking up (a clyster)... Which doesn't mean getting it pregnant.