The main purpose of a Coffee Enema is detoxifying your Liver. Every six minutes all of your blood goes through your liver to be detoxified. When a coffee enema is performed, that time shortens to three minutes, which essentially makes a coffee enema like a purification dialysis cleaning process of the blood. Coffee Enemas work because the hemorrhoidal veins in the descending colon dump into the portal system via the hepatic portal vein. The coffee uses the hepatic portal vein as a direct connection to the liver.