Book excerpt: The field of pediatric FGIDs has grown over the last two decades, and for this reason we have decided to publish a separate book on pediatric FGIDs, which is extracted from the main Rome IV chapter material. This book has an introduction by co-guest editors Samuel Nurko, MD (chair of the Neonate-Toddler Committee) and Carlo Di Lorenzo, MD (chair of the Child-Adolescent Committee).Following this are the two updated and expanded pediatric chapters of Rome IV and also newly validated sets of the pediatric diagnostic questionnaires and criteria, a series of pediatric Multidimensional Clinical Profile (MDCP) cases for the Rome IV book, and a set of diagnostic algorithms for both neonate-toddler and child-adolescent. Thus the pediatric gastroenterologist can possess a complete but compact book on FGIDs relative to his or her specialty.