You will crap like a wild animal if you eat nothing but fruit. I've looked into a lot of different diets and cleanse things people tell me about mainly out of curiosity. If you must do some kind of cleanse this is the best one I've seen http://drbenkim.com/full-body-cleanse-diet.htm
I have never tried this and likely never will. Similar to Joeywhat's advice my diet solution is to eat smaller meals, less meat, more fruits, raw vegs, nuts. Grilled instead of fried, wheat crackers instead of chips, dried fruits and granola instead of cookies, tea instead of coffee. Limit sodium intake, no fast food, no sweets, limited carbonated beverages and make them diet.