Between the 1950s and 1980s, Europe and North America saw a marked increase in the incidence of Crohn's disease in adults. The "North--South" divide in Europe disappeared and the incidence of paediatric Crohn's disease has grown. We are now entering a new era, in which inflammatory bowel disease (IBD), especially Crohn's disease, is emerging in the Asia--Pacific nations. The incidence patterns are mimicking those in Europe five decades ago. This intriguing situation raises many questions. Is this a reflection of "westernisation" of countries in the Asia-Pacific? Can we take advantage of this situation to identify the environmental factors involved in pathogenesis, something we have largely failed to do the first time around? Will the lessons learnt in managing IBD in the past enable the emerging nations to better deal with these illnesses? Will IBD in the Asia--Pacific present behave and respond to therapies as the Western version or will different genetic and environmental backgrounds alter the phenotype of the diseases? Will it be safe to apply the same therapeutic approaches in an endemically infected environment?This book is the proceedings of Falk Symposium 151 on 'Emerging Issues in Inflammatory Bowel Diseases', held in Sydney, Australia, on 24-25 March 2006, the first symposium of its kind both in the southern hemisphere and in the Asia--Pacific region. All contributors are leaders in their field of IBD across a wide spectrum of geographical regions and ethnicity. The book presents the first major text where "East meets West" in IBD. The major issues of concern in the regions where IBD is a relatively common disease include the role of genetic and environmental factors in pathogenesis and disease expression, the application of sophisticated diagnostic tools, and the best use of biological agents in therapy. In contrast, key issues in the emerging nations where IBD is at present relatively rare include characterising the nature and behaviour of IBD in those populations, developing ways of differentiating IBD from infective bowel conditions such as tuberculosis, how to apply standard treatment regimens, and the role of traditional therapies, such as Traditional Chinese Medicine, in the management of IBD. It is the hope of many that the increasing incidence of IBD in the Asia--Pacific region provides important clues as to the nature of environmental factors responsible for this and that these clues lead to preventive measures being taken. We also hope that this book helps prepare emerging nations to deal with a new disease, and helps developed nations to focus on issues of relevance to assist in that quest.