Final answer:
The next best step after a normal physical examination for a child suspected of swallowing a dime is to obtain an X-ray, which is effective for detecting metallic objects and is less invasive than other procedures.
Step-by-step explanation:
The subject of this question is Medicine, specifically within the context of emergency care for children. When dealing with a case where a child is suspected to have swallowed a foreign object like a dime, the next best step is to obtain an imaging study. Since the physical examination is normal, and there is concern about a foreign body in the GI tract, an X-ray would be the most appropriate initial test. This is because X-rays are excellent at showing metallic objects, such as coins, which are radiopaque.
Barium contrast studies should be considered if there's suspicion of complications or anatomic abnormalities after an initial X-ray, but they are not the first-line imaging test for suspected foreign body ingestion. An urgent endoscopy may be warranted if the foreign body has resulted in complications such as obstruction, perforation, or if there is clinical deterioration of the patient. However, this is more invasive and would not be indicated without evidence of a complication or inability to visualize the object on an X-ray. Therefore, starting with a simpler and less invasive X-ray would be more appropriate.