Functional Disorders: Children and Adolescents.

Characterization of childhood and adolescent functional gastrointestinal disorders (FGIDs) has evolved during the two decade long Rome process now culminating in Rome IV. The era of diagnosing a FGID only when organic disease has been excluded is waning,as we now have evidence to support symptom-based diagnosis. In child/adolescent Rome IV we extend this concept by removing the dictum that there was "no evidence for organic disease" in all definitions and replacing it with "after appropriate medical evaluation the symptoms cannot be attributed to another medical condition". This change allows the clinician to perform selective or no testing to support a positive diagnosis of a FGID. We also point out that FGIDs can coexist with other medical conditions that themselves result in gastrointestinal symptoms (e.g., inflammatory bowel disease). In Rome IV functional nausea and functional vomiting are now described. Rome III "abdominal pain related functional gastrointestinal disorders" (AP-FGID) has been changed to functional abdominal pain disorders (FAPD) and we have derived a new term, "functional abdominal pain -not otherwise specified", to describe children who do not fit a specific disorder such as irritable bowel, functional dyspepsia, or abdominal migraine. Rome IV FGID definitions should enhance clarity for both clinicians and researchers.