Caecal faecolith: ultrasonic--radiologic diagnosis.

The entity of caecal faecoliths is not well known to most radiologists. It presents as a hard tender palpable mass in the right iliac fossa. It usually occurs in older women with chronic constipation. On ultrasound it appears as an intracaecal, highly echogenic, shadowing mass. Plain radiographs may show lamellated calcifications. Barium enema shows a well defined intracaecal mass. Using a combination of ultrasound and plain films or barium enema, a preoperative diagnosis should be possible.