Knowledge Does Not Translate Into Diagnostic Restraint: Application of Rome‐Based <scp>IBS</scp> Diagnosis Among Medical Students in Latin America

BACKGROUND: Disorders of gut-brain interaction (DGBIs) are highly prevalent and frequently evaluated using a positive, symptom-based diagnostic framework defined by the Rome criteria. Despite guideline recommendations discouraging routine exclusionary testing in the absence of alarm features, excessive diagnostic evaluation remains common in clinical practice. Whether this pattern originates during undergraduate medical training is unknown. METHODS: We conducted a multicenter cross-sectional study of 238 medical students from 45 universities across 14 Latin American countries. Participants completed a structured survey assessing exposure to DGBI teaching, theoretical knowledge of Rome-based diagnosis, recognition of alarm features, and diagnostic decision-making using sequential standardized vignettes representing a Rome IV-consistent irritable bowel syndrome (IBS) presentation without red flags. RESULTS: Although 74% reported prior DGBI-specific teaching and 69% had heard of the Rome criteria, 70% ordered diagnostic tests in the initial Rome-consistent adult vignette. Testing escalated with increased symptom severity and persisted in 53% despite normal laboratory findings. Misclassification of functional symptoms as alarm features occurred in approximately one-third of respondents. Higher theoretical knowledge was associated with lower initial testing rates (68% vs. 83%, p = 0.010), although unnecessary testing remained common even among high-knowledge students. Only 15% met criteria for high composite clinical performance, and 21% demonstrated discordant high knowledge but poor clinical reasoning. CONCLUSIONS: These findings identify an early divergence between Rome-based diagnostic principles and applied clinical reasoning. Diagnostic overuse in DGBIs may begin during undergraduate training, suggesting that improving education requires not only knowledge transmission but also structured reinforcement of positive diagnosis and diagnostic restraint.