In recent years functional gastrointestinal disorders have attracted much interest. These disorders are extremely common. They are characterized by symptoms and the lack of structural lesions that can be identified with clinically available routine diagnostic tests. Several functional abnormalities are now believed to play a role in the development of the symptoms. This book summarizes the presentations at the International Falk Symposium No. 99 `Functional Dyspepsia and Irritable Bowel Syndrome: Concepts and Controversies' that took place on May 27-28, 1997. This symposium brought together clinical and basic researchers and clinicians to improve interdisciplinary communication. The meeting comprehensively covered basic and clinical aspects of these disorders, and it not only summarized the current knowledge, but also identified scientific questions that need to be addressed in the future.