Psyllium: Good or Bad???

Please tell me if psyllium is good or bad. I have always used it in Bowel Cleanses and sometimes each night with claywater and apple juice. I've always had good results. Recently on the Bowel Cleanse list someone said that it was bad and that it sticks in colon for years, causing problems. Can you tell me about this.
Thanks, Diana of Dewberry Hill Tweet