Related Experiment Video
Updated: Jun 13, 2026
Chronic Salmonella Infection Induced Intestinal Fibrosis
Published on: September 22, 2019
Long-term classification stability and treatment patterns of inflammatory bowel disease unclassified: a longitudinal
Mario Andrea Latorre1,2, Michael Rennie1, Konstantina Rosiou1
1Leeds Gastroenterology Institute, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
Objective:
In patients presenting with inflammatory bowel disease (IBD), it may not be possible to diagnose ulcerative colitis (UC) or Crohn's disease (CD) and a classification of IBD Unclassified (IBD-U) is applied. We aim to describe the long-term natural history and treatment patterns in IBD-U.
Methods:
This analysis was based on the Leeds IBD Steroid Study, a large retrospective study conducted at Leeds Teaching Hospitals (a UK-based tertiary IBD unit) that included all adult patients with an established diagnosis of IBD who had contact with the service between January 2016 and December 2017 and where access to primary care records were linked to hospital electronic records. Patients with IBD-U were analysed retrospectively. Baseline demographics and treatment patterns of patients with IBD-U were compared with UC and CD. Longitudinal follow-up occurred until 2025 to determine stability of IBD-U diagnosis.
Results:
Of 153 patients with IBD-U, 52% were male; the mean age was 46.6 years, and the mean disease duration was 13.1 years. Patients with IBD-U were less likely to receive mesalazine (85%) compared with UC (92%, p=0.0058) but more likely than patients with CD (44%, p<0.0001). Biologics were more often used for IBD-U (21%) than UC (9.5%, p<0.0001) but less often than CD (51%, p<0.0001). Steroid use and use of healthcare resources were higher in IBD-U than in UC and CD. 12 patients (7.8%) were reclassified as UC, 6 patients (3.9%) were reclassified as CD and 135 patients (88.2%) remained classified as IBD-U at the end of follow-up.
Conclusion:
IBD-U remains largely a stable diagnosis over long-term follow-up. Patients with IBD-U exhibit distinct therapeutic patterns and increased healthcare utilisation compared with UC and CD. These findings underscore the clinical relevance of IBD-U as a persistent phenotype and highlight the need to optimise treatment decisions and reduce the burden associated with diagnostic uncertainty.
Related Concept Videos
01:17Chronic Bowel Disorders: Introduction
Irritable Bowel Syndrome (IBS) is a common disorder affecting the gastrointestinal tract. The distinctive feature is recurrent abdominal pain associated with altered bowel movements, manifesting as constipation, diarrhea, or fluctuating between both. The...
01:26Inflammatory Bowel Disease I: Introduction
01:30Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the colonic...
01:20Inflammatory Bowel Disease IV: Clinical Manifestations
01:27Inflammatory Bowel Disease I: Ulcerative Colitis
Inflammatory bowel disease, or IBD, encompasses a group of disorders characterized by chronic inflammation or ulceration of the gastrointestinal tract.
Risk Factors
The exact cause of IBD remains unclear, although it is believed to be due to a mix of genetic, environmental, microbial, and immune factors. Genetic factors are significant in determining susceptibility to IBD, with family history being a critical risk factor. Individuals with a first-degree relative who has IBD are at...
01:25Inflammatory Bowel Disease III: Crohn's Disease