How can you clean your intestines?
Intestines clean themselves. See below for more:
Keep in mind that the gut is a very complicated organ:
with all the folds that are within it, the surface area of the gut ends up being more than 40X larger than the surface area of the skin,
there is a massive amount of bacteria and other "flora and fauna" that lives within the gut that helps to digest our food - all of which is important to digestion,
and there is a lot of activity dedicated to keeping the intestines clean.
This video from TedX talks about the gut and the connection to the gut and the rest of the body.
This link talks about popular views of gut and colon cleansing and the fact that it can be risky: