Colon cleansing involves giving an enema (colonic) containing some salt, and sometimes coffee or herbs to remove food that, according to proponents, remains in the colon, producing nonspecific symptoms and general ill-health. However, the colon usually does not require any help cleaning itself. The practice can be potentially dangerous if incorrectly practised.
For much of history, clean living was a lifestyle focused on living a good and moral life. Clean meant abstaining from vices like alcohol, gambling, sexual acts that might be deemed perverse or unlawful, cursing, dishonesty, and, in general, things that just weren’t wholesome or appropriate. You can see a devotion to clean living in the spur of movements like Prohibition.