When someone accidentally swallows a metal object, such as a coin, staple, small screw, or piece of jewelry, it is a significant medical concern. Unlike dietary trace minerals, the body is not equipped to handle the size, shape, or potential toxicity of solid metal items. Understanding the pathway and risks involved is important.
Immediate Danger: Lodging in the Esophagus
The most immediate risk occurs when a metal object becomes lodged in the esophagus. This structure has narrow points where objects frequently become stuck. Lodging here can pose a choking hazard or compress the adjacent airway, leading to noisy or difficult breathing.
Symptoms of this obstruction often include acute difficulty swallowing (dysphagia) or excessive drooling due to the inability to keep down saliva. Patients may also report chest pain, gagging, or vomiting attempts. If the object remains stuck for more than 24 hours, even if smooth, it can cause pressure necrosis, increasing the risk of perforation and requiring immediate intervention.
Natural Passage Through the Body
If a small, blunt, non-toxic metal object successfully passes the esophagus and enters the stomach, the chances of it exiting the body without incident are high. Approximately 80% to 90% of ingested foreign bodies pass spontaneously through the gastrointestinal tract. Once in the stomach, the object is propelled by peristalsis, the muscular contractions of the digestive tract.
The typical transit time is between 24 and 72 hours, though it can take up to seven days to be fully passed in the stool. Objects smaller than 2.5 centimeters in diameter and shorter than 5 centimeters are the most likely to pass without issue. Patients are often advised to monitor their stool to confirm the object has exited, provided they remain asymptomatic. Digestive acids and enzymes do not significantly break down solid metal, so the object remains intact.
Recognizing Serious Complications
While many objects pass without issue, certain characteristics increase the risk of serious complications.
Sharp Objects and Perforation
Sharp objects, such as needles, open safety pins, or broken pieces of metal, carry the highest perforation risk. Perforation can cause internal bleeding and allow digestive tract contents to spill into the abdomen. Symptoms of mechanical complications like obstruction or perforation include severe abdominal pain, vomiting, fever, and blood in the stool or vomit.
Batteries and Toxicity
A specific danger is posed by button or coin-sized lithium batteries. If a battery becomes lodged in the esophagus, saliva triggers an electrical current that generates hydroxide, a caustic substance. This chemical reaction can cause severe liquefaction necrosis—a type of burn—in as little as two hours, potentially leading to perforation or a life-threatening fistula. Ingesting heavy metals like lead is also a concern, as the stomach’s acidic environment can leach the toxic material, leading to systemic poisoning over time.
When Medical Removal is Necessary
Management begins with a diagnostic assessment, typically involving X-rays, since most metallic items are radiopaque. Imaging helps determine the object’s size, shape, and exact location, which dictates the urgency and method of removal. Most cases follow an initial period of observation, but intervention is necessary if the object is high-risk or fails to progress.
Endoscopic removal is the preferred method for objects stuck in the esophagus or stomach. This minimally invasive procedure uses a flexible tube with a camera and specialized tools like retrieval nets or grasping forceps. Endoscopy is urgently performed for sharp objects, lodged batteries, or any object causing severe symptoms. Surgical intervention is rare, required in less than 1% of cases, and is reserved for confirmed intestinal obstruction, perforation, or failed endoscopic attempts.