A novel technique for assessment of biliary secretion and enterohepatic circulation in the unrestrained conscious rat.

1. A technique is described for the continuous collection of bile, for long periods, from unrestrained conscious rats housed in standard glass metabolism cages. 2. Bile is collected in cooled vessels outside the cage through a cannula which is exteriorized at the back of the neck and is protected from damage by an outer covering. 3. A minimum recovery period of three days is allowed after the operation, by which time liver function and intestinal motility are normal. 4. An extension of the technique can be used to assess enterohepatic circulation.