The case of a four-year girl who swallowed 18 magnetic balls is a timely reminder to consider foreign body ingestion when otherwise healthy kids present with colicky abdominal pain, her treating doctors say.

The girl presented with a 10-day history of vomiting and abdominal and pain, and more recently constipation, which had been diagnosed as acute gastroenteritis and gastritis at other hospitals.

On examination, she was playful with normal vitals and a soft, non-tender abdomen and no palpable mass, say doctors from the King Saud University in Riyadh, Saudi Arabia.

An ultrasound, blood tests and urine analysis were also normal, but an abdominal X-ray showed a collection of 18 radiopaque objects in the right, lower abdomen with distended bowel loops, they wrote in the European Journal of Medical Case Reports.