During the 7th International Bile Acid meeting held in Cortina d'Ampezzo. , Italy, during March 1982, there were two important Workshops dealing with recent advances in two areas of bile acid metabolism - Serum Bile Acids i,n Health and Disease and The Pathophysiology of the Enterohepatic Circulation. These Workshops complemented the broad range of topics in bile acid metabolism which were presented formally as part of a Postgraduate Course. The proceedings of these formal presentations have already been pub- lished by MTP Press under the title Bile Acids in Gastroenterology but in view of the exciting, important, new information which emerged during both Workshops, the organisers of the meeting felt that it would be valuable to record and edit the proceedings of the Work- shops, which form the basis of this volume. The advent of new techniques for measurement of total and indi- vidual bile acids in serum now means that accurate and reliable 7 PREFACE measurements of bile acids in peripheral circulation are available to all. This has resulted in a veritable explosion of information in the serum bile acid field and, therefore, the appearance of a critical evalu- ation of the technical and basic scientific and clinical aspects of measuring serum bile acids is indeed timely.