RESUMO
ABSTRACT BACKGROUND: Functional gastrointestinal disorders (FGIDs) are defined as a variable combination of chronic or recurrent gastrointestinal symptoms that are not explained by structural or biochemical abnormalities. Their relationship with prematurity has been increasingly studied. OBJECTIVE: To compare the frequency of FGIDs in preterm and term infants and to evaluate whether invasive procedures during the neonatal period in preterm infants are associated with greater likelihood of FGIDs in the first two years of life. DESIGN AND SETTING: Controlled nested cross-sectional study conducted in a Brazilian university hospital. METHODS: This was a controlled nested cross-sectional study on a retrospective cohort of infants born preterm who were compared with infants born at term regarding the presence of FGIDs. Medical consultations were conducted by a single pediatric gastroenterologist to obtain information on the gestational and neonatal periods and on clinical manifestations of the digestive tract. The Rome IV criteria for the diagnosis of FGIDs were used. RESULTS: A total of 197 infants (< 24 months), including 99 preterm and 98 term infants, were studied. Infant regurgitation was more prevalent in term infants (35.1% and 15.6%; P < 0.001). The frequencies of other FGIDs (infant colic, functional constipation, functional diarrhea and infant dyschezia) in preterm infants did not differ from those of term infants (P > 0.05). No relationship was found between invasive procedures during the neonatal period and development of FGIDs in preterm infants. CONCLUSION: Infants born preterm did not have higher frequency of FGIDs in the first two years of life.