I suspect that it's unlikely that you did any damage to your colon or rectum, assuming the coffee enemas were not taken at temperatures more than a few degrees above body temperature.
The fact that your bowels are moving on their own most days puts you in a category that many people would envy.
The next day that your bowels don't move on their own by bedtime, why not try a saline solution (1 teaspoon of Sea Salt or plain non-iodized table salt per pint of pure water) enema and see what results you get from a full bag, if you can take it all or as much as possible.