Diagnostic yield of dual-phase computed tomography enterography in patients with obscure gastrointestinal bleeding and a non-diagnostic capsule endoscopy

Background and Aim: In patients with obscure gastrointestinal (GI) bleeding, capsule endoscopy is widely used to determine the source of bleeding. However, there is currently no consensus on how to further evaluate patients with obscure GI bleeding with a non-diagnostic capsule endoscopy examination. This study aims to determine the diagnostic yield of dual-phase computed tomographic enterography (CTE) in patients with obscure GI bleeding and a non-diagnostic capsule endoscopy. Methods: Patients with obscure GI bleeding who were referred for capsule endoscopy were prospectively enrolled. Obscure GI bleeding was defined as overt if there was obvious GI bleeding; otherwise it was defined as occult. Patients with a non-diagnostic capsule endoscopy and no contraindications underwent a CTE. Results: Capsule endoscopy was performed in 52 patients; 26 patients (50%) had occult GI bleeding and 26 patients (50%) had overt GI bleeding. CTE was then performed in 25 of the 48 patients without a definitive source of bleeding seen on capsule endoscopy. The diagnostic yield of CTE was 0% (0/11) in patients with occult bleeding versus 50% (7/14) in patients with overt bleeding (P < 0.01). Using clinical follow up as the gold standard, for the 25 patients with a non-diagnostic capsule, CTE had a sensitivity of 33% (95% confidence interval 0.15, 0.56) and a specificity of 75% (95% confidence interval 0.22, 0.99). Conclusions: In patients with a non-diagnostic capsule endoscopy examination, CTE, is useful for detecting a source of GI bleeding in patients with overt, but not occult, obscure GI bleeding.