The effects of a coffee enema are different than a saline enema. The most important difference between a saline enema and a coffee enema is the presence of caffeine in the coffee. Caffeine, theophylline and theobromine, combine to stimulate the relaxation of smooth muscles causing dilatation of blood vessels and bile ducts. The effects of having a coffee enema are not the same as drinking coffee. The veins of the anus are very close to the surface of the tissue. The caffeine is therefore absorbed more quickly (and in higher concentration) than it is in when coffee is drunk.
