HISTORY
A healthy 4-year-old girl passed a threadlike object in her stool at a day-care center. She had no diarrhea, vomiting, or abdominal pain. Stool had no blood or melena. Child’s appetite normal.
Patient born in Canada of a middle-class family. No history of traveling.
PHYSICAL EXAMINATION
Active, alert, well-nourished patient. Height, 101 cm (50th percentile); weight, 15.2 kg (25th percentile). Physical findings normal. In particular, no excoriation noted in the perianal area. No signs of anemia.
WHAT’S YOUR DIAGNOSIS? (Answer on next page)
