A case report in BMJ Case Reports describes the successful removal of eight swallowed nails from a woman's colon using cap-assisted colonoscopy. The patient, in her 30s with a history of pica and anxiety disorder, presented with abdominal pain after intentionally ingesting the nails—her sixth such episode in a year. The nails initially moved through the digestive tract but clustered near the ileocecal valve after four days of conservative management, prompting endoscopic intervention.
The medical team attached a hard, transparent cap to the distal end of the colonoscope to protect the mucosal lining while grasping the sharp objects. Using a snare, they secured each nail beneath the cap and withdrew it, achieving complete removal with only minor superficial abrasions. The authors note that sharp foreign bodies reaching the lower GI tract are rare, and there are no established guidelines for such cases.
While the procedure was successful, the authors acknowledge limitations: advancing the cap through a tortuous colon can be challenging, and the cap itself may cause trauma. They emphasize that this technique should be reserved for clinically stable patients without perforation or peritonitis, and only performed by experienced endoscopists with surgical backup readily available. The patient refused psychiatric admission and was followed as an outpatient, with no complications one year later.