Hello, Lulu, welcome to the forum.
When you drink coffee or any other caffeine product, the caffeine works towards weakening the adrenals which leads to increased inflammation in the body due to low levels of anti-inflammatory corticosteroids. As far as Candida is concerned, it becomes more difficult for the healing process to be successful when the adrenals are weak. Also the tannins in the coffee can bind together nutrients that are needed for healing. In addition to this, the oxalates in coffee irritate the body tissues. But the most important of these is the weakening of the immune system which in most cases is already suffering due to the Candida infestation.
The information above can be applied to coffee enemas since when the liquid enters the body part of it is absorbed into the blood stream.