No pre-prep necessary. Start on a Friday, or whenever your "weekend" is. That way you can figure out your tolerance level and how many caps to take. I took 4 capsules the first night, had mild cramping the next morning, and good elimination. Took 6 caps the next night, had no cramping and GREAT elimination the next morning. Built up to 10 caps a night for the remainder of the bottle of Oxypowder for an intense cleanse. It liquifies everything. Its been two weeks and I have gotten rid of a lot of gunk. I feel great. Bloating is greatly reduced. I had a couple of good eliminations the first hour of the day, then not much for the rest of the day. Had another good one in the evening after using my treadmill. I never experienced any urgent runnings to the bathroom, this has not disrupted my routine at all.
I wish you great success with this product.