Which imaging modalities are most effective for confirming a diagnosis of large bowel obstruction in adults?

The most effective imaging modality for confirming a diagnosis of large bowel obstruction in adults is computed tomography (CT) scanning. CT provides detailed cross-sectional images that allow identification of the site, cause, and severity of obstruction, as well as complications such as ischemia or perforation, making it the preferred diagnostic tool in clinical practice ¹.

Plain abdominal X-rays may be used initially to detect signs of obstruction, such as dilated bowel loops and air-fluid levels, but they have limited sensitivity and specificity compared to CT ¹. Ultrasound is generally less useful in adults for large bowel obstruction due to bowel gas interference but may have a role in specific cases or in paediatric populations (Carroll et al., 2016).

Recent radiological literature supports CT as the gold standard for diagnosing large bowel obstruction, emphasizing its superiority in identifying neoplastic causes and uncommon etiologies, which are critical for guiding management (Hayakawa et al., 2013; Somwaru and Philips, 2017).