The liver excretes some drugs (unmodified or conjugated) into the bile. Unmodified drugs can obviously be reabsorbed from the small intestine. Drugs which are excreted conjugated (to glucuronide, glutathione or sulphated) into the bile may have the bond cleaved by bacteria in the gut and then be reabsorbed.

Activated charcoal can bind drug that would otherwise be reabsorbed and whole bowel irrigation can 'flush' drug through thus interrupting the 'cycle'.