Ten days every six months is the standard recommendation for maintenance cleansing.
If you have issues, as I do with my colon, you can fast much longer and more frequently with excellent results. Always make sure your body is fully recovered from one cleanse before beginning another. I am sure you are fine after the one you did in May...
What are your goals? I plan to do a series of short (ten day) fasts, with cleansing diet between this year, as opposed to the 60 day straight shot I did last summer. I am much cleaner, and those long fasts are a bear to break! I will keep everyone informed as to the difference.
Best to all,