Fecal impaction detection on a bone scan.

and posterior spot views of pelvis were obtained, which revealed the same finding (fig. 1). Horizontal images of computed tomography (CT) (fig. 2) showed a mass in the retrovesical region consistent with fecal impaction in rectum (posterior to the bladder). The zone of absent radiotracer activity in posterior projection images of the pelvis was attributed to attenuation of gamma rays by impacted fecal materials.