What do you mean what is good? It's basically cleansing the colon....lots of junk can get stuck in there over time and cleaning it can restore it to it's best functioning state. However, there are some risks associate with this method, so it would depend on whether or not it was medically necessary to do this. You can cleanse your colon in much safer ways.

http://www.quackwatch.com/01QuackeryRelate dTopics/gastro.html

You might want to post in the stomach/ulcers/gastric bypass/colon disorders forum for more information about this.