You can take colosan while taking fiber but not clay, as the clay could interfere with the action of the colosan. Best to take the fiber during the day, and then dose up on the colosan at night so it works while you're sleeping. Some of the mucilogous (sp?) herbs might interfere too, but I'm not sure. You can try doing kinesiology and see if the herbs are right for you, while you're taking Colosan. :)