What can I do to clean out my colon?

Fiber and water. By far the best is fiber and water. There are other salt solutions that pull water through the bowels but that is temporary. High fiber and water can be a lifestyle.
Protease purge. Need protease 1 million units twice a day with modified citrus pectin 1500mg twice a day and chlorella will clean gut. Do the above for a week.Replenish gut with galactan and kefir to regrow healthy bacteria.