Swallowed foreign bodies in children

Written by the X-Ray Atlas editorial team from the sources listed below · Medical review pending · Updated 24 October 2026 · Level: Beginner

Young children explore the world with their mouths, and swallowed objects are a common reason for an emergency visit. Most objects pass harmlessly. A few do not, and the X-ray's job is to answer three questions quickly: is there an object, where is it, and is it one of the dangerous ones? The most dangerous common object is the button battery, which can burn through the oesophagus (esophagus) within hours. It looks very like a coin on a quick glance. This page teaches how to tell them apart, where objects lodge, and what an X-ray cannot show.

1. Which films to take

• For a swallowed radiopaque object, many departments use a single frontal film covering the neck, chest and abdomen in small children, so that the whole route is seen. Older children may need separate chest and abdominal films. Follow local protocol.
• Include the neck: the upper oesophagus is the most common place for an object to stick, and it is easy to cut off the top of a chest film.
• Add a lateral view if the object is in the neck or chest, or if you need to distinguish a coin from a battery, or the oesophagus from the airway.
• Not every swallowed object needs an X-ray. An asymptomatic child who has swallowed a small, smooth, non-battery, non-magnetic object may be managed clinically. Some centres use handheld metal detectors for coins. Local guidance decides.
• If the object might be a battery or a magnet, or the child has symptoms (drooling, pain, vomiting, refusing to eat, breathing problems), image promptly.

2. Where objects stick

The oesophagus has three natural narrowings, and these are the classic sites of impaction:

1. Cricopharyngeus at the thoracic inlet (about C6): the most common site.
2. The level of the aortic arch, where the arch and left main bronchus indent the oesophagus.
3. The gastro-oesophageal junction, just above the diaphragm.

Once an object is in the stomach, most will pass through the rest of the bowel. Objects can occasionally stop at the pylorus, the duodenal curve or the ileocaecal valve. A child with previous oesophageal surgery (for example after repair of oesophageal atresia) is more likely to have objects stick at a stricture.

3. Coin: oesophagus or trachea?

A flat disc in the neck or chest is almost always in the oesophagus. The classic teaching on orientation is:

	Frontal (AP) view	Lateral view	Why
Oesophagus	Seen en face, as a full circle	Seen edge-on, as a line	The oesophageal opening is wider side to side, so the coin lies in the coronal plane.
Trachea	Seen edge-on	Seen en face	The tracheal rings are incomplete posteriorly, so the trachea is wider front to back and the coin lies in the sagittal plane.

A coin in the airway is rare, and a child with an airway object is usually symptomatic. If there is any doubt, take a lateral. A coin lodged in the oesophagus usually needs removal; one that has reached the stomach usually passes.

4. Button batteries: the emergency

Button (disc) batteries are found in remote controls, watches, toys, car keys and greetings cards. When one lodges in the oesophagus, it creates an electrical current through the moist lining that causes a chemical burn. Serious damage can begin within about 2 hours. Complications include perforation, strictures, tracheo-oesophageal fistula, vocal cord palsy and catastrophic bleeding from a fistula into the aorta, sometimes days or weeks after removal. Larger lithium cells (about 20 mm across) are the most dangerous.

How to tell a battery from a coin

• Double ring or halo sign on the frontal view: a round object with a second, inner circle or a rim, because the battery is made of two layers of different diameter. A coin is a uniform disc.
• Step-off on the lateral view: the edge of the battery shows a step where the two layers meet. A coin has parallel, straight edges.
• On the lateral, the narrower side (the negative pole) is the side that causes most damage. The radiologist may comment on which way it faces.

Next step: an oesophageal battery needs immediate referral for endoscopic removal. Some UK guidance supports giving honey (or sucralfate in hospital) to children over 1 year while awaiting removal, if the ingestion was within about 12 hours, to coat the battery and reduce injury. This must never delay transfer or removal, and you should check current national and local guidance, which is evolving. A battery that has passed beyond the oesophagus is managed according to local or national guidance (for example the ESPGHAN position paper): many can be observed, but some need removal or repeat imaging, especially if the child is very young, the battery is large, or a magnet was also swallowed.

5. Magnets, sharp objects and radiolucent objects

• Magnets: a single small magnet usually passes. Two or more magnets, or a magnet with another metal object, can attract each other through loops of bowel and cause pressure necrosis, fistulas, perforation and obstruction. Multiple magnets may look like a single object on one view, so a lateral can help. Refer urgently.
• Sharp objects (pins, needles, bones) carry a risk of perforation, especially in the oesophagus. Many are thin and hard to see.
• Radiolucent objects: plastic toys, wood, most food and some glass may be invisible. A normal X-ray does not exclude a swallowed object. If symptoms persist, endoscopy or other imaging may be needed.
• Signs of complications: free gas under the diaphragm (see pneumoperitoneum), gas in the neck soft tissues or mediastinum (see pneumomediastinum), or bowel obstruction.

For adult foreign bodies, body packing and rectal objects see foreign bodies on X-ray.

6. Inhaled foreign bodies

An inhaled (aspirated) object is a different and more dangerous problem. The typical story is a toddler who coughed or choked while eating, especially nuts.

• Most inhaled objects are radiolucent (nuts and food), so the object itself is rarely seen.
• The X-ray shows indirect signs: air trapping with a hyperlucent, over-expanded lung on the affected side (a ball-valve effect), collapse or consolidation beyond the obstruction, and mediastinal shift away from the affected side on expiration.
• Expiratory films or, in young children who cannot cooperate, lateral decubitus views help: the normal dependent lung loses volume, while the obstructed lung stays inflated.
• In young children the right and left main bronchi are affected almost equally, unlike adults, where the right is more common.
• A normal chest X-ray does not exclude an inhaled foreign body. If the history is suggestive, refer for bronchoscopy.

7. Pitfalls and mimics

• Calling a battery a coin: zoom in on every round object and look for the double ring. Look at the lateral for a step-off.
• Not including the neck, so an object at the cricopharyngeus is missed.
• External objects: clothing poppers, hair clips, earrings and ECG electrodes can mimic swallowed objects. Remove what you can and check that the object moves with the patient's anatomy on two views.
• Stacked objects: two coins or two magnets may overlap exactly on one view.
• Satisfaction of search: a child may have swallowed more than one object.
• Rotation mimicking hyperlucency: a rotated chest film can make one lung look darker. Check rotation before calling air trapping (see image quality).

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	Coin orientation in the oesophagus and trachea, the halo sign, and why a battery is an emergency.
Nurse	Ask specifically about batteries and magnets, keep the child nil by mouth if removal is likely, and escalate drooling, breathing problems or bleeding.
Junior doctor	Image promptly if a battery or magnet is possible, look at every round object closely, and refer oesophageal batteries for immediate removal following current guidance.
Radiographer	Include the neck, add a lateral when the protocol allows or the object is in the chest, and remove external artefacts first.
Advanced / FRCR	Battery orientation, multiple magnets, complications after removal and subtle indirect signs of an inhaled object.

Practise on paediatric X-rays →

References

1. Child Accident Prevention Trust. Button batteries. capt.org.uk
2. Birk M, et al. Removal of foreign bodies in the upper gastrointestinal tract in adults: European Society of Gastrointestinal Endoscopy (ESGE) clinical guideline. Endoscopy 2016;48(5):489–496. esge.com
3. Mubarak A, et al. Diagnosis, management and prevention of button battery ingestion in childhood: an ESPGHAN position paper. J Pediatr Gastroenterol Nutr 2021;73(1):129–136.
4. Radiopaedia. Button battery ingestion. radiopaedia.org
5. Royal College of Radiologists. iRefer: making the best use of clinical radiology. irefer.org.uk

For education only. Not a substitute for a formal report, senior review or your local policy. Never use this page to make decisions about a real patient.