Bowel obstruction is a common cause of stomal complications of ileostomy. We report a case in which sonography revealed 2 well-defined, rounded, hyperechoic structures, measuring 1.7 cm in diameter and causing dense acoustic shadowing, in the lumen of the bowel of a 3-year-old boy with a permanent end ileostomy. Endoscopy showed the structures to be freely mobile plum stones in the fluid-filled terminal ileum. This case demonstrates the usefulness of sonography in the diagnostic workup of patients with ileostomy obstruction.