Figure 1b. Active sigmoid bleeding in a 94-year-old woman who presented with bright red blood from the rectum. (a, b) Axial (a) and coronal (b) CT angiograms demonstrate active contrast material extravasation into the sigmoid colon (arrow). Note the multiple colonic diverticuli in this region and the contrast material–filled diverticulum that is optimally demonstrated on the coronal image, presumably representing the site of hemorrhage. (c) Findings on an IMA angiogram confirm the presence of active sigmoid bleeding (arrowheads). The patient was treated successfully with coil embolization.