Diet for colon cleanse;

I have been searching information online that may help me choose the right diet for colon cleanse . I once tried a colon cleanser but it was so harsh that I had to spend most of my time sitting in the toilets. It did not show any results instead it had so many adverse effects on my body. I used to feel lethargic and dull. I suffered from constipation and several other digestive disorders. Then I realize how important it to choose the right diet or supplement is. Now I do not buy any new product without consulting my physician once.