Do distinct functional dyspepsia subtypes exist in children?

ACKGROUND AND AIM: Two different subtypes of functional dyspepsia (FD) are recognized in adults: epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS). The aim of the study was to assess the presence of FD subtypes in childhood at diagnosis and to observe changes at follow-up. METHODS: A total of 100 patients with a diagnosis of FD based on pediatric Rome III criteria were consecutively enrolled. FD subtypes were successively classified through adult Rome III classification. Children were revaluated after 6 months of follow-up (T1). RESULTS: At T0, 17 (17%) of 100 patients were classified as EPS, whereas 47 (47%) of 100 patients fulfilled criteria for PDS. In 36 (36%) of 100 children an overlap between the 2 subtypes was identified. Nausea was significantly higher in PDS and overlap groups when compared with EPS (χ = 21.7, P = 0.0001; χ = 20.7, P = 0.0001). Headache was significantly increased in PDS and overlap groups compared with patients with EPS (χ = 9.8, P = 0.001; χ = 13.1, P = 0.0001, respectively). At T1 among children belonging to PDS group at enrolment, 9 of 47 (19.1%) changed to EPS group, and 9 of 47 (19.1%) changed to the overlap group. Five (29.4%) of 17 patients and 2 (11.8%) of 17 children diagnosed as having EPS at T0 switched to PDS and overlap group, respectively. Of the 36 patients with overlap at enrollment, 11 (30.6%) satisfied criteria for PDS, and 7 (19.4%) switched to EPS group. CONCLUSIONS: Two distinct FD subtypes are identifiable in pediatric population. A high percentage of overlap and a variation of subtype over time were found, suggesting a common pathophysiologic mechanism.