I've always been a big believer in spankings and enemas going hand in hand.
I've given a slave spanking and enemas sessions. Large volume enema, allowed to expel and then straight back on the bed for spanking, caning or a paddling. Then a repeat enema, expulsion and back on the bed for another implement. I'd usually repeat the process about 3 times. No question about who is in charge after a session like that.
Other subs I've either given the spanking or paddling during the administration, OTK or on my table or administered the enema and the made then hold it while I administer a suitable and enjoyable punishment. I was told but 2 subs that holding and being given a hard paddling was a deeply moving experience for them.