Early childhood-onset rumination syndrome is clinically distinct from adolescent-onset rumination syndrome

Objectives: Rumination syndrome (RS) beginning in early childhood or infancy is understudied and challenging to treat. Our objective is to compare the characteristics and outcomes of early-onset (EO) and adolescent-onset (AO) patients with RS.Methods: We conducted an ambidirectional cohort study of children diagnosed with RS at our institution. Patients were included in two groups: EO (RS symptom onset <= 5 years and diagnosis <= 12 years) and AO (onset >12 years). Patient characteristics, severity, and outcomes were compared between the groups.Results: We included 49 EO and 52 AO RS patients. The median ages of symptom onset and diagnosis in EO were 3.5 and 6 years, respectively; AO, 14.5 and 15 years. EO RS had a slight male predominance while AO was predominantly female (p = 0.016). EO patients were more likely to have developmental delay (24% vs. 8%, p = 0.029) and less likely to have depression (0% vs. 23%, p < 0.001) or anxiety (14% vs. 40%, p = 0.004). At baseline, EO RS was less severe than AO RS: EO RS had greater regurgitation frequency (p < 0.001) but lower vomiting frequency (p = 0.001), resulting in less meal skipping (p < 0.001), reliance on tube feeding or parenteral nutrition (p < 0.001), and weight loss (p = 0.035). EO RS symptoms improved over time: at follow-up, patients had lower regurgitation (p < 0.001) and vomiting frequency (p < 0.001) compared to baseline.Conclusion: EO RS is clinically distinct from AO RS, with differences in sex distribution, comorbid conditions, and severity of initial presentation. The pathogenesis and natural history of EO RS may be distinct from that of AO RS. [GRAPHICS]