Objectives: To determine the frequency of chronic inflammatory bowel diseases and patient characteristics with reference to endocrinological manifestations of the disease in children and adolescents hospitalized in the Children's Disease Clinic of KBC Split from 2011 to 2021. Materials and methods: 94 patients with chronic inflammatory bowel disease in the Children's Disease Clinic of KBC Split from 2011 to 2021. Data from medical records were analyzed: age, incidence of general and gastrointestinal symptoms and extraintestinal manifestations, puberty status, TV, BMI , fecal calprotectin, 1,25(OH)2D3 and disease activity index. Results: Among the patients, 60 (63.8%) were boys and 34 (36.2%) were girls. The incidence of chronic inflammatory bowel diseases in our sample varies from 0 to 10.6 per 100,000 for Crohn's disease, for ulcerative colitis from 0 to 7 per 100,000 and for the indeterminate form from 0 to 2.3 per 100,000 children and adolescents. The majority of patients (88%) have TV-SD in the range of 0 to 2 SD. Among patients, 54.3% are in the range of BMI-SD deviation from > -2 SD to 0 SD. 71% of patients have a reduced value of 1,25(OH)2D3. Conclusions: The incidence of Crohn's disease and ulcerative colitis in the Children's Disease Clinic of KBC Split in the period from 2011 to 2021 does not differ from literature data for Croatia and Southern Europe. In our patients, the frequency of general symptoms is lower, and the frequency of gastrointestinal symptoms is the same, comparing with literature data. The frequency of low TV at the time of diagnosis among our patients is lower than in literature data. There is a smaller percentage of patients in our sample who were obese compared to literature data. The severity of the disease is negatively correlated with TV and positively correlated with BMI at the time of diagnosis. Data on puberty status are not recorded often enough in the medical documentation, which is necessary for expanding knowledge about these diseases. Among our patients, a high proportion has a deficit and/or insufficiency of 1,25(OH)2D3. Calprotectin needs to be further investigated in the pediatric population.