This book celebrates the emergence of knowledge in this field and is written for primary care clinicians to help update the knowledge of pediatric gastroenterology (GI). The current and future shortage of pediatric gastroenterologists necessitates steady, rejuvenated information on GI disorders for primary care clinicians as they care for children and adolescents with complex gastroenterologic dilemmas and disorders. In view of this shortage and the rapidly increasing knowledge in pediatric GI, as well as understanding indications for referral to pediatric gastroenterologists in the 21st century, relavent and assiduous information aimed at primary care clinicians in these areas becomes increasingly important. The authors hope that this book will fill the void. Donald E Greydanus, MD, DrHC (Athens), is professor of pediatrics and adolescent medicine, founding chair of the Department of Pediatric and Adolescent Medicine, Western Michigan University Homer Stryker MD School of Medicine in Kalamazoo, Michigan, United States. Orhan Atay, MD, is assistant professor, Department of Pediatrics, Eastern Virginia Medical School (EVMS) and Director of the Childrens Hospital of The Kings Daughters, Norfolk, Virginia, United States. Joav Merrick, MD, MMedSci, DMSc, born and educated in Denmark is professor of pediatrics, child health and human development affiliated with the Division of Pediatrics, Hadassah Hebrew University Medical Center, Mt Scopus Campus, Jerusalem, Israel, Kentucky Childrens Hospital, University of Kentucky, Lexington, United States and professor of public health at the Center for Healthy Development, School of Public Health, Georgia State University, Atlanta, United States, the medical director of the Division for Intellectual and Developmental Disabilities, Ministry of Social Affairs and Social Services, Jerusalem and the founder and director of the National Institute of Child Health and Human Development in Israel.