Jim, your reply to soccertese just now, relating the bloating and vomiting episode 5 years ago and a doctor's description of an upper GI obstruction suggests that you are dealing with more than simple constipation. If it were me, I would make an appointment with a good gastroenterologist and determine whether that may be a significant factor in what you are struggling with. I'm doubtful that a "cleanse" would be adequate for solving the problem if an upper GI anatomical obstruction is present.
Robert