I quote "When a coffee enema is used, the caffeine from the coffee is preferentially absorbed into this system and goes directly to the liver where it becomes a very strong detoxicant. It causes the liver to produce more bile (which contains processed toxins) and moves bile out toward the small intestine for elimination. This seems to free up the liver to process more incoming toxic materials that have accumulated in the organs, tissues and bloodstream. The coffee does not go into the systemic circulation, unless the enema procedure is done improperly.
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If the constipation is chronic, I suggest a fast. I had major digestive problems and was diagnosed with irritable bowel syndrome, food allergies, sleep disorders, etc by various doctors for years. Nothing worked until on a whim I tried a fast. I did the Master Cleanser fast-- you can find details on the web. On the fourth day I passed a 24 ft tapeworm. Disgusting I know, but I got it from eating undercooked pork in Asia...so now I fast every year for 10 days-- I quite enjoy it actually-- The first three days are difficult, but then your body goes into ketosis--the same thing that happens to people on Atkins and you start to live off your own body fat. I was exercising two hours a day on my last fast and feeling fantastic...