Background: Rome IV criteria promote a symptom-based (“positive”) diagnosis of pediatric disorders of gut–brain interaction (DGBIs). In clinical practice, however, organic gastrointestinal diseases may mimic DGBIs and lead to diagnostic revision after further evaluation. We aimed to quantify the diagnostic stability of an initial Rome IV-oriented functional diagnosis in a tertiary pediatric outpatient setting and to identify symptom phenotypes associated with a higher likelihood of later organic reclassification. Methods: We performed a single-center retrospective cohort study (2014–14 May 2021) based on outpatient chart review. Eligible patients were children and adolescents aged 0–18 years with an initial Rome IV-oriented functional diagnosis. Diagnostic reassessment was based on follow-up data, available laboratory and instrumental investigations, and/or response to exclusion therapies. Final diagnoses after reassessment were categorized as functional only, organic, or mixed. Groups were compared using Pearson’s chi-square test. Results: The cohort included 220 males (50.0%) and 220 females (50.0%), with a mean age of 8.86 ± 4.65 years. After reassessment, 343/440 (77.95%) remained functional, 73/440 (16.59%) were reclassified as organic, and 24/440 (5.45%) were classified as mixed. Final diagnosis differed by GI tract involvement (p = 0.001) and by symptom cluster (p = 0.001). Upper GI/dyspepsia-spectrum presentations showed the highest organic yield (27.03%), followed by lower abdominal pain/IBS-spectrum presentations (19.61%). Diarrhea and vomiting/cyclic vomiting each showed 16.67% organic diagnoses (mixed: 10.0% and 7.14%, respectively), whereas constipation showed the greatest diagnostic stability (98.89% functional; 1.11% organic). Functional confirmation rates were similar before and during the pandemic (77.71% vs. 78.70%; p = 0.756). Monthly case volume was higher in 2020–2021 (6.29 vs. 4.61 cases/month). Conclusions: In this tertiary cohort, about one in six children initially diagnosed with a functional disorder were later found to have an organic disease, and an additional 5% had mixed organic–functional presentations. Diagnostic revision was associated with presenting phenotype, with the highest organic yield observed in dyspepsia/upper GI presentations and the lowest in constipation. These findings support symptom-stratified evaluation and follow-up alongside Rome IV criteria.
Caimmi et al. (2026) studied this question.