Long-term clinical course, treatment patterns, and prognosis in pediatric-onset vs. adult-onset IBD: a multicenter retrospective cohort study in Korea

Purpose: This study aimed to compare the long-term clinical characteristics, treatment patterns, and prognosis of inflammatory bowel disease (IBD) in patients diagnosed before and after 18 years of age. Methods: A retrospective study was conducted using data from 384 patients with IBD with a disease duration exceeding 10 years across five hospitals. Baseline characteristics, disease status, and treatment patterns were analyzed at diagnosis, 5 years, 10 years, and present. Results: Of the 384 patients, 84 (21.9%) and 300 (78.1%) were diagnosed before and at or older than the age of 18 years, respectively. Patients diagnosed before 18 years of age more frequently presented with Crohn’s disease (CD) (83.3% vs. 40.0%), whereas ulcerative colitis (UC) was predominant in those diagnosed later (16.7% vs. 60.0%). Younger patients had a significantly higher prevalence of abdominal pain (64.3% vs. 48.7%), malnutrition/weight loss (21.4% vs. 10.7%), and anal fistulas/abscesses (26.2% vs. 5.7%) at the time of diagnosis. Younger patients had more pancolitis-type UC (50% vs. 32.2%) and more perianal diseases in the CD group (51.4% vs. 20.8%). Younger patients initially exhibited higher rates of steroid usage, with a gradual shift towards biologics, such as infliximab. Multivariable Cox regression identified discontinuation of biologic therapy during follow-up as a significant risk factor for disease recurrence. Conclusion: Our findings suggest that the age at IBD onset significantly is associated with disease progression and treatment outcomes, underscoring the need for age-tailored management strategies in long-term IBD care.