Figure 21a. Initial manifestation of Crohn disease in a 26-year-old woman who presented with right-sided groin pain. (a) Unenhanced helical CT scan shows several tethered small intestinal loops in the right lower quadrant, with findings suggestive of enteroenteric fistulas (arrow). No obstructing stone was found. (b) CT scan obtained after oral and intravenous administration of contrast material enables better delineation of the enteroenteric fistulas (arrow).