When my hubby and I exchange enemas dudring a recreational session, we usually alternate giving/receiving, so the time lapse between enemas is the time the partner takes to accept and expell. However, we never rush enemas, try to provide as much pleasure during the giving and receiving so the sesssion (and aftermath) are totally enjoyable. We love the frolic and pleasuring that goes on during the giving/receiving and we can also do things to each other during explusion.
My hubby likes to fill the enema bag with warm (not hot) water when I'm expelling and using just a single-opening nozzle, sprays water 'you know where" and I'm sure to orgasm.
For him, I return the favor by filling the bag with cold water, out of the tap, and spray it "you know where" ... he goes absolutely wild when this happens. He once did the cold water treatment on me ... it was a kick, but I got more enjoyment from the warmer water. Cold just turned me off ... don't know why ... he listened to what I suggested.
One time, very recently, when accepting anenema, I inserted a small vibrator ... kept it in until all was expelled ... wow wow wow ... I was totally exhausted.
When it's for medical purposes, the receiver pretty much dictates when the second and third enemas should be taken ... but the time has seldom been more than 15 minutes from the beginning of explusions of one enema to receiving the next enema.