Rinawi F, et al. - This study involved the elucidation of extent change in pediatric-onset ulcerative colitis (UC) during long-term follow-up determined using the Paris classification. Researchers also examined the predictors of extent change. In pediatric-onset UC, disease extent appeared to change considerably over time. Data shed light on the connection between the presence of extraintestinal manifestation and higher pediatric UC activity index score at diagnosis with progression from limited to extensive disease during follow-up.