Management of Foreign Body Ingestion Not Visible on X-ray

Diagnostic Approach

• A negative X-ray does not rule out foreign body ingestion, and a CT scan should be performed in symptomatic patients or those with high clinical suspicion, as plain radiography has false-negative rates up to 47% for esophageal foreign bodies and up to 85% for food bolus, fish bones, chicken bones, and non-radiopaque objects 1, 2
• The overall false-negative rate for esophageal foreign bodies is up to 47%, and for food bolus impaction, fish or chicken bones, it is 85% 1, 2
• CT scan has 90-100% sensitivity for detecting foreign bodies, and its specificity is 93.7-100% 1, 2, 3

Imaging Recommendations

• CT scan should be performed in patients with suspected perforation or persistent symptoms despite negative X-ray 1, 2
• CT is essential for locating non-radiopaque objects, evaluating complications, and assessing bowel obstruction 1, 2, 4, 5, 6

Endoscopy Timing

• Emergent endoscopy (within 2-6 hours) is recommended for complete esophageal obstruction, sharp-pointed objects, button/disk batteries, and magnets 1, 2, 3
• Urgent endoscopy (within 24 hours) is recommended for other esophageal foreign bodies without complete obstruction, and food bolus impaction without complications 1, 2, 3

Laboratory Workup

• For symptomatic patients or those requiring intervention, obtain complete blood count (CBC), C-reactive protein (CRP), blood gas analysis, and serum creatinine and inflammatory markers if perforation is suspected 1, 2, 6, 3, 7, 8

Location-Specific Considerations

• Esophageal foreign bodies require intervention due to risk of aspiration and perforation, and during endoscopy, attempt gentle pushing into stomach first, then retrieval if pushing fails 1, 2, 3
• Anorectal foreign bodies may not be visible on X-ray, and CT scan is the next step for non-radiopaque objects, with digital rectal examination performed carefully after imaging 4, 5, 6, 7, 8

Immediate Endoscopic Evaluation for Esophageal Symptoms

Introduction to Urgent Endoscopy

• The World Journal of Emergency Surgery recommends urgent endoscopy within 24 hours to evaluate for a retained pill or pill-induced esophageal injury, as persistent symptoms for three days indicate either a persistent foreign body or significant mucosal damage that requires direct visualization 9, 10

Diagnostic Considerations

• Therapeutic flexible endoscopy is the first-line treatment for persistent esophageal foreign bodies and should be performed urgently (within 24 hours) for esophageal foreign bodies without complete obstruction 9, 10
• Endoscopic evaluation should be performed even if radiographic examination is negative when patients have persistent esophageal symptoms 9, 10
• The sensation of a pill being "stuck" combined with persistent, worsening sore throat for three days suggests either retained medication or pill-induced esophagitis requiring direct assessment 9, 10

Red Flags for Emergency Evaluation

• Complete inability to swallow saliva indicates complete esophageal obstruction requiring emergent endoscopy 9, 10
• Fever, persistent chest pain, breathlessness, or tachycardia suggests possible perforation requiring immediate CT scan with oral contrast 11, 12

Endoscopy Objectives

• Direct visualization to identify retained pill fragments or food bolus 9, 10
• Assessment of mucosal injury - pills can cause chemical burns, ulceration, or stricture formation even after passing 9, 10
• Therapeutic intervention - gentle pushing of any retained material into the stomach or retrieval if necessary 9, 10

Post-Endoscopy Care

• Patients with pill-induced esophagitis typically require acid suppression therapy and dietary modifications 13
• Avoid alcohol, bulky food, spicy or hot foods, citrus products during healing 13
• Follow-up endoscopy may be needed if stricture develops 11, 12

Management of Fishbone Ingestion

Diagnosis and Evaluation

• Plain radiographs miss up to 85% of fish bones, making negative imaging unreliable for excluding retained foreign bodies 14
• CT scan has 90-100% sensitivity compared to only 32% for plain X-rays in detecting fish bones 14
• All patients reporting fishbone ingestion should undergo CT scan of the neck and chest to accurately locate the bone and assess for complications 14
• Complete blood count, C-reactive protein, and lactate should be screened for early inflammatory response 14

Treatment and Management

• Flexible endoscopy within 24 hours is recommended if symptoms persist or imaging suggests retained foreign body 14
• Emergent endoscopy is required for complete inability to swallow saliva, sharp-pointed fish bones visible on imaging, or signs of perforation such as fever, chest pain, subcutaneous emphysema, or respiratory distress 14
• Sharp-pointed fish bones visible on imaging carry up to 35% perforation risk and require emergent removal 14
• The American College of Surgeons recommends referring to ENT for thorough oral and pharyngeal examination, flexible endoscopy, and CT scan interpretation by specialists familiar with fish bone complications 14

Evidence‑Based Recommendations for Foreign Body Ingestion Management

Imaging Strategy

• Initial plain radiographs (AP and lateral neck, chest, abdomen, pelvis) should be obtained to identify radiopaque objects, locate the foreign body, assess size/shape, and detect pneumoperitoneum. – World Journal of Emergency Surgery recommendation 15
• If plain films are negative but the patient remains symptomatic, a contrast‑enhanced CT scan is mandatory; CT provides 90–100 % sensitivity compared with only ~32 % for plain X‑rays. – World Journal of Emergency Surgery recommendation 15
• CT scanning is also required when perforation is clinically suspected or when symptoms persist despite negative radiographs. – World Journal of Emergency Surgery recommendation 15

Laboratory Workup

• In patients with suspected perforation, add serum lactate and procalcitonin to the basic work‑up (CBC, CRP, blood gas, creatinine). – World Journal of Emergency Surgery recommendation 15

Anorectal Foreign Body Management

• Obtain an abdominal X‑ray before performing a digital rectal examination to avoid injury from unseen sharp objects. – World Journal of Emergency Surgery recommendation 15
• For low‑lying anorectal objects, attempt bedside (manual) extraction as the first step. – World Journal of Emergency Surgery recommendation 15
• For high‑lying objects (located above the rectosigmoid junction), prioritize endoscopic extraction as the first‑line approach. – World Journal of Emergency Surgery recommendation 15
• After removal of any anorectal foreign body, perform proctoscopy or flexible sigmoidoscopy to evaluate the bowel wall for injury. – World Journal of Emergency Surgery recommendation 15

Surgical Indications

• Immediate surgery is indicated for patients who are hemodynamically unstable. – World Journal of Emergency Surgery recommendation 15
• Transanal extraction must not be attempted in the presence of perforation or hemodynamic instability. – World Journal of Emergency Surgery recommendation 15

Critical Pitfalls (Safety Alerts)

• Do not delay advanced imaging (CT) in hemodynamically unstable patients; proceed directly to operative management. – World Journal of Emergency Surgery recommendation 15
• Avoid endoscopic retrieval of suspected drug‑containing packages because of the high risk of package rupture. – World Journal of Emergency Surgery recommendation 15

Imaging Modalities for Metallic Foreign Body Ingestion

Ultrasound as a Radiation‑Free Diagnostic Tool

In pediatric patients, bedside ultrasound can be used to locate metallic foreign bodies within the gastrointestinal tract without exposing the child to ionizing radiation. Evidence shows a 95 % sensitivity for detecting foreign bodies in soft‑tissue locations, although ultrasound cannot visualize objects that are embedded in bone. 16

Contraindication of MRI for Suspected Metallic Ingestion

Magnetic resonance imaging should be avoided when a metallic foreign body is suspected because the magnetic field can cause heating, movement, and severe artifact of the metal, posing a safety risk. Prior to any MRI examination, a plain radiographic screen is recommended to rule out the presence of metallic objects. 16