Children commonly swallow foreign bodies. Coins are the most commonly swallowed foreign body that comes to medical attention in the USA; in other countries, those related to food, such as fish bones, are most common. Pre-schoolers of both sexes, adolescent boys, and children with mental health issues are at highest risk. Even infants may swallow foreign bodies that are given to them, perhaps by older siblings. Most swallowed foreign bodies will harmlessly pass through the GI tract, but some will lead to health problems if they become lodged (too big to pass, such as a spoon, or small objects like a pill that adheres to a moist surface); traumatize the mucosa (sharp or pointed object, like a razor blade or pin), or cause burn-like illness (biologically active, such as a button battery or a medication patch) may cause problems.
Accidental or deliberate ingestion.
The most common complication of foreign body ingestion in children is having the swallowed object lodged in the esophagus, although they may become lodged anywhere in the GI tract. Once lodged, they may partially or completely obstruct the GI tract. Some may erode through the GI tract, causing complications due to perforation or foreign body migration.
A foreign body that has lodged in or injured the esophagus may cause chest pain or a foreign body sensation. Symptoms may be more notable when swallowing. Younger children may drool, gag, vomit or refuse food. There may be hematemesis. Some will cough. A foreign body lodged in the stomach or intestines may cause abdominal pain, vomiting, or bloody stools. If present for a prolonged period, fever or weight loss may develop. A foreign body that completely obstructs the esophagus will cause more dramatic symptoms. Importantly, there may be no signs or symptoms, or they may be subtle and hard to recognize. Since many foreign body ingestions by children are unwitnessed, the possibility of non-specific symptoms being caused by foreign body ingestion should always be kept in mind.
Swallowed foreign bodies that contain nickel may cause systemic signs and symptoms, such as rash or pruritus, in patients with nickel sensitivity.
If a complete history and physical examination, including examination of the pharynx, suggest possible foreign body ingestion, the provider must decide whether or not to initiate imaging, usually plain radiographs. Healthy children with recent, low-risk ingestions may be simply observed. Metallic swallowed foreign bodies, such as coins and batteries, will show up readily on a plain radiograph. Metal detectors are occasionally used, especially in the setting of known coin ingestion. It is not unusual to find an unexpected foreign body on a radiograph obtained for evaluation of non-specific symptoms, such as a cough, fever, or weight-loss. Most glass fragments are visible on a radiograph. Radiolucent objects, such as a large piece of meat or a plastic toy, may not be apparent on radiographs, although their edges or irregularities may still be noticeable on radiography. Affected patients may require more advanced imaging techniques, such as contrast-enhanced radiography or MRI scanning, but the patients may also be considered for treatment (e.g., endoscopy) without further imaging.
Button/disc batteries may cause serious injury when lodged in the esophagus, nose, ear, etc. for even a brief period. The highest risk is associated with larger lithium based batteries, but all models carry some risk. Children with suspected button/disc battery ingestion should be managed urgently; a battery lodged in the esophagus should be removed without delay. Treatment algorithms for button/disc battery ingestions are widely available. (ref) A button/disc battery may be distinguished from a coin when seen on a radiograph by its characteristic two-layer appearance when seen on-end, or a circle-within-a-circle appearance when seen front-to-back. (photo?)
Small, powerful magnets, such as those found in some toys and games, may cause serious injury to the intestines, as the strong attraction between two or more magnets may cause them to erode through intervening tissues. A single swallowed magnet in combination with another metallic object, most notably a button/disc battery, may also cause injury.
Pre-existing GI tract abnormalities, such as previous surgery, strictures, fistulas, diverticula, or functional abnormalities, increases the risk of a swallowed foreign body becoming lodged at the site of the abnormality.
Unusual or recurrent foreign body ingestion should prompt consideration of psychosocial concerns. Foreign body ingestion may be risk-taking or attention-seeking behavior. Abuse or neglect may be present. Mental illness may lead some children to swallow foreign bodies. This may be inadvertent, such as the patient with bulimia who loses grip on a toothbrush used to induce vomiting and swallows it. Packets of drugs may be swallowed to avoid detection by police.
Prevention of foreign body ingestion in children is a high priority. Caregivers should be educated about preventing small children from contact with small objects that may be harmful if swallowed, especially button/disc batteries, small magnets, and other high-risk objects. This includes items placed into a trash container that may make accessible to children.
Most children who have swallowed a foreign body do not require treatment. Asymptomatic, previously healthy children who have swallowed low-risk foreign bodies will typically do well. Patients/caregivers should be instructed on the signs/symptoms of subsequent complication. 
Foreign bodies that are lodged in the esophagus are most commonly removed endoscopically. Some, especially those lodged in the lower esophagus at the gastroesophageal junction, will pass spontaneously into the stomach after a few hours; this is safe for coins and similar small, inert objects, in children with otherwise normal GI tracts who are at low risk of further complication as the object passes through the remainder of the GI tract. Some centers will remove small esophageal foreign bodies, especially coins, with a bougie or a balloon catheter; these require substantial experience. Endoscopy is also typically used to remove large, sharp/pointed, or other high-risk objects from the stomach, or in patients for whom continued passage of the object through the GI tract poses a risk. Objects in the lower GI tract should be managed in conjunction with a specialist, who may recommend surgical removal.
Medical management of foreign body ingestion is not recommended. Emetics, muscle relaxants, and meat tenderizers are typically ineffective, and are potentially dangerous, in the treatment of children with esophageal foreign bodies. Laxatives are occasionally used to promote the passage of objects from the intestines, but this practice has not been proven effective.
Management of children who have swallowed foreign bodies requires an interprofessional approach. Physicians, nurses, poison control specialists, radiology technologists, child life specialists, ambulance personnel, and others must work together to provide continuous, child-friendly care, both acutely and in follow-up. (Levels III, IV, and V) The nurse should educate the parent and caregiver about the dangers of leaving small items around children. In addition, parents should be told never to keep button batteries around children as they are known to cause rapid damage to the GI tract. (Level V)
The majority of ingested foreign bodies pass through the gastrointestinal tract without any complications. In rare cases, the retained foreign body may cause ulceration, perforation, bleeding or localized stricture formation. The most dangerous foreign bodies are button batteries which can rapidly cause mucosal injury. Magnets are also known to cause mucosal injury in the small bowel leading to perforation. In rare cases, complications are also known to occur during removal of the foreign body- usually from the anesthesia. (Level V)