Terminal Ileitis on Imaging Is Rarely Crohn's Disease: A 10-Year Retrospective Cohort Study

Terminal ileitis is a common radiological finding in patients with abdominal pain and altered bowel habits. Although often associated with Crohn's disease (CD), it has a broad differential diagnosis including infectious, surgical, and malignant conditions. Prior studies suggest 20%-45% of terminal ileitis accounts for CD. This study aimed to evaluate the proportion of patients with computed tomography-detected (CT) terminal ileitis diagnosed with CD and to assess clinical and biochemical predictors.

A retrospective cohort study was conducted at a single tertiary hospital between 2014 and 2024. Adult patients with CT findings of terminal ileitis were included. Data were collected on demographics, laboratory values, stool testing, and endoscopic evaluation. Multivariable logistic regression was used to identify predictors of CD.

Of 128 patients, 16 (12.5%) were diagnosed with CD. Infectious (27.7%) and surgical (17.9%) etiologies were the most common causes of non-CD terminal ileitis. Stool testing within 72 h was performed for 48.4% of patients, with 35.5% positive for pathogens. Endoscopic evaluation was performed in 59 patients (46%), and histopathological inflammation identified in 43.5% of biopsied cases. Lower albumin levels trended toward association with CD and were independently associated with CD on multivariable analysis (OR 0.82, 95% CI 0.72-0.94, p = 0.004).

After evaluation, a small minority (12.5%) of patients with CT-detected terminal ileitis were diagnosed with CD. Hypoalbuminemia was a significant predictor of CD, whereas routine inflammatory markers had limited diagnostic value. Larger prospective studies are needed to further refine the diagnostic algorithms for detection of CD in patients with terminal ileitis.