Swallowing a piece of metal depends on the object’s characteristics, including its size, shape, and material. While most swallowed foreign objects pass through the digestive tract without incident, ingesting metal requires immediate attention and careful monitoring. The body’s anatomy and digestive processes determine whether an object is relatively safe or poses an immediate threat to the gastrointestinal system.
Immediate Danger of Obstruction and Perforation
The initial dangers occur in the upper gastrointestinal (GI) tract, specifically the esophagus and stomach. Large or blunt metal objects can become lodged, most commonly in the narrowest points of the esophagus, causing an obstruction. This blockage can lead to chest pain, an inability to swallow (dysphagia), and sensations of choking. Such objects must be removed quickly to prevent localized tissue damage.
Sharp metal objects, such as pins or fragments with jagged edges, pose a high risk of puncturing the delicate lining of the GI tract. Perforation is a medical emergency where the object tears a hole in the wall of the esophagus or intestine. This allows digestive contents and bacteria to leak into the sterile chest or abdominal cavity, leading to life-threatening infection and inflammation. Signs of this complication include sudden, severe abdominal pain, fever, and vomiting, sometimes with blood.
Ingestion of button batteries, which contain lithium or alkaline chemicals, is a serious hazard. When a button battery lodges in the esophagus, saliva completes an electrical circuit, causing rapid chemical and electrical burns to the surrounding tissue. This process can cause severe, irreversible damage and tissue necrosis in as little as two hours, necessitating emergency removal.
The Digestive Journey and Monitoring Passage
Once a metal object passes through the esophagus and the pylorus (the valve leading out of the stomach), the immediate risks decrease significantly. The digestive system’s natural process, known as peristalsis, takes over. Peristalsis involves involuntary muscle contractions that propel contents through the small and large intestines.
The ability of the object to pass relies heavily on its dimensions. Objects over 2.5 centimeters in diameter or six centimeters in length are less likely to clear the tight turns of the small intestine. For most small, blunt objects, the journey through the intestines takes between four to six days, though passage may be delayed up to four weeks before the object is expelled.
During observation, a regular diet is maintained to promote normal bowel function and encourage passage. Individuals are instructed to inspect their stool until the object is recovered, confirming the period of risk has ended. If the object is radiopaque (visible on X-ray), serial imaging may be used to track its movement through the abdomen.
When to Seek Medical Attention and Treatment
Immediate emergency room intervention is required if an individual develops specific symptoms following metal ingestion. These warning signs include severe or rapidly worsening abdominal pain, persistent vomiting, or the presence of blood in the vomit or stool. Developing a fever or chills suggests a complication, such as infection or peritonitis resulting from a perforation.
Diagnosis and Imaging
Medical professionals first use diagnostic imaging, most commonly plain X-rays, to locate the object and determine its size, shape, and position. X-rays are effective for metal objects, which are clearly visible against soft tissue. Computed Tomography (CT) scans may be used if a complication like perforation or abscess formation is suspected, as they provide detailed cross-sectional images of the GI wall.
Endoscopic Removal
If the metal object is high-risk or lodged in a dangerous location, medical intervention is initiated for removal. Endoscopy is the primary non-surgical method, involving the insertion of a flexible tube equipped with a camera and retrieval tools through the mouth. This procedure is performed urgently for sharp objects located in the stomach or duodenum, or emergently for any object, especially a battery, stuck in the esophagus.
Surgical Intervention
Surgery is reserved for cases where the object has caused a severe complication or cannot be removed endoscopically. Evidence of perforation is an indication for surgery, which necessitates immediate repair of the GI tract wall. Surgical intervention is also considered if a blunt object remains stationary in the small intestine for more than one week, indicating an intestinal obstruction that has failed to resolve.