Pylorus Endoluminal Functional Luminal Imaging Probe Measurements in Children Are Determined by Age and Are Distinctly Different From Adult Values

Background/Aims: The pylorus muscles are known to play a vital role in the process of gastric emptying and are directly implicated in symptom associated with delayed gastric drainage.Endoluminal functional luminal imaging probe (EndoFLIP) can predict clinical response to pylorus directed therapy in symptomatic children and adults.Normal pylorus EndoFLIP values are available for adult but not in children.We aim to assess the impact of age on pediatric pyloric EndoFLIP values.Methods: Retrospective review of all children who underwent pylorus EndoFLIP in Evelina London Children's Hospital from July 2022 to March 2025.Results: One hundred and sixty-nine EndoFLIP values were collected from 29 children, 35% females.Mean age was 8.5 ± SD (± 4.1), children reported at least 1 symptom of impaired gastric emptying.EndoFLIP values appeared to cluster in age ranges 0-4, 4-8 and > 8 years with diameter significantly different.There was no correlation with weight range.At balloon volume of 40 mL, abdominal distension after feeding positively correlated with distensibility (r = 0.45, P = 0.018 and negatively with pressure (r = -0.41,P = 0.036).Intolerance to gastric feeding with pressure (r = 0.45, P = 0.019) and pain after feeding with pressure (r = 0.5, P = 0.009).High balloon pressure can lead to unwarranted dilatation.Conclusion: Pediatric pylorus EndoFLIP values are determined by age but not weight and they correlate with symptoms of impaired gastric emptying.Adults normal values are not applicable to children.There is a need to set up a separate pediatric protocol for pylorus EndoFLIP.