Practically no disease comes into the body uninvited, and an impaired liver with poor bile flow is an engraved invitation card.
The liver's primary function is to remove toxins and it passes those toxins out via the bile duct. As cancer pioneer Max Gerson observed, he never found cancer except with patients whose liver was impaired. He also insisted that patients on his protocol take frequent coffee enemas to keep the bile duct open and flowing.
Besides coffee enemas, in my opinion the best things to keep the bile duct open and functioning properly are lecithin with choline and coconut oil. Beet juice is also supposed to be good. And I recommend milk thistle as an absolute must for good liver health. Other beneficial supplements include alpha lipoic acid, seleium and turmeric.