This comparative matched-cohort study aims to evaluate the diagnostic performance of contrast-enhanced photon-counting computed tomography (PCCT) for detecting small gastrointestinal lesions compared with energy-integrating detector dual-energy computed tomography (DECT). The study includes a prospectively enrolled PCCT cohort and a retrospectively identified DECT cohort. Endoscopy with histopathology serves as the reference standard. Primary evaluation focuses on lesion detection, with additional assessment of lesion characterization, image quality, quantitative imaging parameters, and interobserver agreement.