The natural course of inflammatory bowel disease-indeterminate from childhood to adulthood: within a 25 year period

Background: Inflammatory bowel disease (IBD)-indeterminate is a subgroup of IBD that has features of both ulcerative colitis (UC) and Crohn's disease (CD). Aims: To determine the clinical course of IBD-indeterminate in children over a 25 year period. Methods: We performed a retrospective investigation on children diagnosed with IBD. Diagnosis and disease distribution of IBD was based on clinical, radiologic, endoscopic, and histologic examinations. Results: Four hundred and twenty children diagnosed with IBD between 1986 and 2003 were identified from the IBD registry, 78 (22%) of whom were diagnosed with IBD-indeterminate. The mean age at diagnosis was 9.2 +/- 4 years and the mean follow-up period was 4.1 +/- 2 years. In 2003, 18 of 78 children (23%) were reclassified by the same physician based on the endoscopic and pathologic findings as follows: eight children with CD, five children with UC, and five children with non-IBD (eg, eosinophilic colitis). During 2011, 20 of the 60 patients who had maintained an IBD-indeterminate diagnosis were located and contacted, and detailed telephone interviews were conducted by the corresponding author. Two patients were reclassified as having CD (10%), one patient was reclassified as having eosinophilic colitis (5%), six patients remained with IBD-indeterminate (30%), and eleven patients (55%) reported a complete resolution of their symptoms. The follow-up period ranged from 10-18 years (mean 12.5 +/- 3 years). Children who were reclassified as having CD were significantly younger than those who maintained an IBD-indeterminate diagnosis (6.4 +/- 4 years versus11.2 +/- 3 years, respectively, P=0.05). Conclusion: Children with IBD-indeterminate remain classified as IBD-indeterminate, or were clinically reclassified as CD or non-IBD, or became asymptomatic as they transitioned into adulthood. The need for IBD-indeterminate classification is of importance, especially when deciding on management and treatment.