Foreign bodies on X-ray

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

Foreign bodies reach the gut by being swallowed, accidentally or deliberately, or by being inserted into the rectum. Most swallowed objects pass through without harm, but some cause obstruction, perforation or chemical injury, and a few are emergencies whatever their size. The X-ray answers four questions: is there an object, where is it, what is it, and is there a complication such as free gas or obstruction? It also has clear limits: many materials are invisible on a plain film. This page focuses on adults; children have a dedicated page, swallowed foreign bodies in children.

1. What is visible on X-ray?

Usually visible	Variable	Usually not visible
Most metals: coins, batteries, magnets, pins, needles, razor blades, keys	Glass (most glass is visible, depending on size and type), some plastics, fish and chicken bones (depending on type and size)	Wood, most plastics, food, aluminium ring-pulls can be faint, many drug packets

An object that cannot be seen may still be there. When the history is convincing and the film is negative, the next step depends on where the object is likely to be and what it is: endoscopy, CT or, for soft tissue foreign bodies, ultrasound.

2. Which films to take

• For a swallowed object of unknown position, films usually cover the neck, chest and abdomen, because objects lodge at narrowings: the cricopharyngeus, the level of the aortic arch, and the gastro-oesophageal junction. Some departments use a single "mouth to anus" film in children; in adults, targeted films are more usual.
• A lateral view helps to show whether an object is in the oesophagus or airway, and whether a disc is a coin or a button battery.
• CT is used when a complication (perforation, abscess) is suspected, for objects that are not radiopaque, for fish bones in the oesophagus (where plain films are unreliable), and for body packing.
• An erect chest X-ray looks for free gas or pneumomediastinum after a sharp object or a prolonged impaction.

The European Society of Gastrointestinal Endoscopy (ESGE) guideline advises against routine radiological evaluation for non-bony food bolus impaction without complications, and advises against barium swallow because it coats the oesophagus and makes endoscopy harder.

3. Oesophageal foreign bodies and food bolus

• In adults, the most common oesophageal impaction is a food bolus, often meat, frequently in people with an underlying narrowing such as a stricture, a ring or eosinophilic oesophagitis. It is usually invisible on X-ray unless it contains bone.
• A patient who cannot swallow their own saliva (drooling, spitting) has a complete obstruction: this needs urgent endoscopy.
• Coins in the oesophagus usually lie face-on (a full circle) on the frontal film and edge-on on the lateral, because the oesophagus is wider side to side. An object in the trachea classically shows the opposite pattern. Airway foreign bodies are much less common.
• Bones in the neck (fish, chicken) may be faint. Soft-tissue swelling in front of the cervical spine on a lateral neck film, or gas in the soft tissues, suggests impaction or perforation. A negative film does not exclude a bone; endoscopy or CT is used when symptoms persist.

4. The dangerous objects

Button batteries

• On the frontal film a button battery shows a double ring or halo because of its two-layered structure. On the lateral, a step-off at the edge is often seen. A coin has neither.
• A button battery lodged in the oesophagus is an emergency. It generates an electrical current in the tissues that causes alkaline injury, and severe burns can develop within about 2 hours, leading to perforation, fistula into the trachea or aorta, and death.
• It must be removed endoscopically immediately. Do not wait for symptoms. National UK guidance for children (see the paediatric page) includes measures such as honey or sucralfate before removal in some circumstances; check current national guidance.
• Batteries that have passed beyond the oesophagus usually pass safely, but management depends on size, symptoms and local guidance.

Magnets

Multiple magnets (or a magnet plus a metal object) can attract each other across loops of bowel, compressing the walls between them and causing necrosis, fistula, perforation and obstruction. On the film, several magnets may appear to sit together as one object. A single magnet is less risky. Multiple magnets need urgent discussion with the surgical or endoscopy team.

Sharp and long objects

Needles, pins, razor blades, toothpicks and bones can perforate, especially at the narrowings and in the duodenal loop and ileocaecal region. Sharp objects in the oesophagus are removed urgently. Long objects (more than about 6 cm) are less likely to pass the duodenum. See ESGE guidance for the details of timing.

5. Rectal foreign bodies

• An AXR shows the shape, size, position and orientation of a radiopaque object, which helps plan removal. Many inserted objects (glass, metal, some plastic) are visible; others need CT.
• Always look for free gas on the AXR and an erect chest X-ray, because rectal or sigmoid perforation changes management completely.
• Approach the patient with dignity and without judgement; delays in presentation are common and increase the risk of complications.

6. Body packing

Body packers swallow, or insert, packets of drugs for smuggling. On the AXR:

• multiple uniform oval or rectangular packets, of similar size and shape, in the bowel;
• the double-condom sign: a thin lucent rim of gas trapped between the layers of wrapping;
• the rosette sign: gas trapped in the knot at the end of a packet.

The plain film has limited sensitivity: packets of similar density to faeces can be missed. Low-dose CT is more sensitive and is used in many centres. A ruptured packet can cause rapid, life-threatening drug toxicity, so a symptomatic body packer is a medical emergency. "Body stuffers", who swallow drugs hastily to avoid arrest, usually carry poorly wrapped packets that are often invisible.

7. Complications to look for

• Perforation: free intraperitoneal gas, pneumomediastinum and surgical emphysema in the neck.
• Obstruction: dilated bowel proximal to an impacted object or a bezoar. See small bowel obstruction.
• Aspiration during an oesophageal impaction: consolidation on the chest film.
• Retained surgical items after an operation (for example swabs with a radiopaque marker thread) are a different problem and a Never Event in England; see artefacts and mimics.

8. Mimics

• External objects: clothing fasteners, jewellery, piercings, ECG electrodes. Ask the patient to remove them, or re-image.
• Tablets and other ingested medication (iron, some enteric-coated tablets) can be radiopaque.
• Calcification: phleboliths, stones and calcified nodes. See abdominal calcification and stones.
• Medical devices: clips, stents, IUDs, and contrast in the bowel from previous studies.

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	What is radiopaque, the oesophageal narrowings, coin versus button battery, and the dangers of magnets.
Nurse	Drooling or inability to swallow saliva needs urgent escalation. Keep the patient nil by mouth if removal is likely.
Junior doctor	Identify the object type and level, look for complications, and escalate batteries, magnets and sharps immediately. Remember that a negative film does not exclude a radiolucent object.
Radiographer	Coverage from the neck to the abdomen when the position is unknown, and a lateral to characterise a disc-shaped object.
Advanced / FRCR	Body packer imaging, CT for radiolucent foreign bodies, and complications of impaction.

Practise on abdominal X-rays →

References

1. 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;48:489–496. esge.com
2. Child Accident Prevention Trust. Button batteries. capt.org.uk
3. Royal College of Radiologists. iRefer: making the best use of clinical radiology. irefer.org.uk
4. Radiology Masterclass. Abdominal X-ray tutorials. radiologymasterclass.co.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.