Terminal Ileal Ulcers: Causes and Diagnostic Approach

Common Causes

The European Crohn's and Colitis Organisation recommends that Crohn's disease is the most frequent cause of terminal ileal ulcers, characterized by transmural inflammation that can occur throughout the gastrointestinal tract but commonly affects the terminal ileum 1
Ulcerative colitis may present with "backwash ileitis," which is continuous extension of inflammation from the cecum into the terminal ileum, seen in up to 20% of patients with extensive colitis, according to the European Crohn's and Colitis Organisation 2
Microscopic colitis (collagenous or lymphocytic colitis) can occasionally involve the terminal ileum with increased intraepithelial lymphocyte count and subepithelial collagen deposition, as reported by the European Crohn's and Colitis Organisation 3, 4
Yersinia, Salmonella, Shigella, Campylobacter species, and Cytomegalovirus can cause terminal ileal ulcers, particularly in immunocompromised patients, as stated by the European Crohn's and Colitis Organisation 5

The European Society of Gastrointestinal Endoscopy recommends that ileocolonoscopy with biopsies is essential for diagnosis, with multiple biopsies taken from both visible lesions and normal-appearing mucosa 6
Severe inflammation is characterized by wall thickening of 3-5 mm, presence of ulcerations, or high T2 intramural signal on imaging, according to the Radiological Society of North America 7

The European Society of Gastrointestinal and Abdominal Radiology recommends that cross-sectional enterography (CT or MRI) can help assess the extent and severity of terminal ileal inflammation, with findings of severe inflammation including marked wall thickening, intramural edema, and small ulcerations 7, 8

The European Crohn's and Colitis Organisation states that Crohn's disease is characterized by focal (discontinuous) chronic inflammation, transmural involvement, granulomas (non-crypt related), while ulcerative colitis with backwash ileitis shows continuous inflammation extending from colon to terminal ileum 2, 6
Infectious causes may show specific histological features depending on the pathogen, as reported by the European Crohn's and Colitis Organisation 5