["Pediatric-onset Crohn's disease (CD) is a heterogeneous disorder which is subjected to progression and complications in a substantial proportion of patients.", 'We aimed to assess the progression in pediatric-onset CD phenotype on long term follow up.', 'Medical charts of pediatric onset CD patients with at least 10 years follow-up were analyzed retrospectively. Disease phenotype was determined at diagnosis and during follow up at different time points. Phenotype was determined according to the Paris classification. The impact of possible predictors on phenotype progression was assessed as well as the association between different therapeutic regimens during disease course and phenotype progression.', 'Progression of disease location, behavior, and perianal involvement was observed in 20%, 38% and 20% of patients, respectively, after a median follow-up of 16.4 (±4.4) years. Microscopic ileocolonic disease at diagnosis was significant predictors for progression of disease extent. Treatment with anti tumor necrosis factor-ɑ agents and number of flares per years of follow-up were associated with progression of disease extent, behavior and perianal involvement.'] Do evolution of disease phenotype in pediatric-onset Crohn 's disease after more than 10 years follow up-Cohort study?