Steven,
You can edit the colonoscopy interval for an individual patient. In a patient note, click on decision support to show the large HM box. RIGHT click on the colonoscopy rule, and you can change the interval for that patient. I am not sure that the date works correctly though, if I set 5 years, it then shows next date 1-5 years hence. Hopefully this will get worked out.
I really like the HM section. I have created some new rules to remind me of things I want to check or follow. After I do ROS, I go to HM section to query patient about these items.