Introduction: Inflammatory bowel diseases are chronic, immune-mediated diseases that include CB, UC and unclassified UBC. They are most often manifested in adolescence. Clinically, they are manifested by diarrhea with admixture of blood, abdominal pain and weight loss. Although the incidence of UBC has been on the rise recently, with timely diagnosis and adequate therapy, disease remission and patients' quality of life can be achieved. Aim: To present the epidemiological and clinical characteristics of patients with UBC and to analyze the diagnostic work-up in patients with suspected UBC. Methods: A retrospective study included an analysis of the medical records of 33 children admitted for suspected inflammatory bowel disease and a total of 15 hospitalizations due to exacerbation of existing inflammatory bowel disease at the Pediatric Clinic of KBC Rijeka in a five-year period (January 1, 2019-December 31, 2023). Results: The median age of children admitted with suspected UBC is 14 years. The majority were male children (56.7%) compared to female children (43.3%). The most frequently recorded symptoms of UBC were diarrheal stools, the appearance of blood in the stool, abdominal pain and weight loss. In all subjects, the diagnosis was established on the basis of the pathohistological findings of the sample obtained by biopsy of the intestinal mucosa during endoscopy. Of the 15 hospitalizations due to worsening of the underlying disease, 80% were due to UK, and 20% were due to CB. Conclusion: Due to the global increase in the incidence of UBC in children, timely diagnosis and appropriate therapy are needed to put the disease into remission and thereby maintain the quality of life of children.