Good question. I would suggest that if you are already clean, ie. your colon, then you don't need to do an enema before the treatment. It is shocking how much stuff we carry around inside; this is why many people do a Colon Cleanse using colonix or something before. A good colon clean takes at least 2 weeks at a minimum. If however, you have done that, and your are clean, then it probably isn't necessary. Some people do a colon flush before the treatment, and it can't hurt.
The idea is to let the stones have free passage out the door as soon as possible after we do the liver flush. After my first flush I didn't do a enema for 2 days, which was a mistake, because when I did do one I had about 50 stones that should have been blown out 2 days before. Someone suggested that our bodies can re-absorb the cholesterol which we dump from the gallbladder and liver after the treatment.