Colonic cleansing has a dark side, according to this monograph, which looks at the inside story:
BONUS: Christina Frangou’s take on the matter.
BONUS: The prince of colonic cleansing.
BONUS: One man’s view about “How to Make a Coffee Enema” and “How to take a coffee enema”
BONUS: “A Bottoms-Up Summary of Past and Recent Impressions Regarding Coffee Enema“, from which this passage may give you the general flavor:
Dr. Wynder broke the ice speaking in a booming, German-accented voice, and with a twinkle in his eye, “I don’t know about you gentlemen, but I would rather have a coffee enema any day than a bone marrow transplant.” Laughter exploded around the table.