I think you need to cease taking that product immediately. A quality colon cleansing product is not supposed to give you diarrhea. Severe diarrhea can cause your body all sorts of problems.
I agree with others that a 7day cleanse is not enough for most colon cleansing products, like Colonix or Blessed herbs. However, there are products out there that do a great job at thoroughly cleansing the colon in a 7 day period. Oxypowder is one that I use and I have never had any complaints about it.
But oxypowder works differently than Colonix. Colonix uses herbs to bulk up inside the colon. Oxypowder is the exact opposite. It literally melts the stuff inside the colon. Makes it much easier to have a bowel movement. But i'm no expert on either product. Just a consumer of both.
Either way. I would stop taking RAPID before you hurt yourself.