Colon Collectibles: Unearthing Coin-Shaped Treasures in Kidney Disease

Introduction: Differentiating ingested foreign bodies and radio-opaque medications is critical due to their similar radiographic appearances. We present a case of a patient with end-stage kidney disease (ESKD) who was found to have sucroferric oxyhydroxide tablets in his colon, initially misinterpreted as metallic foreign bodies. Case Description: A 69-year-old man with ESKD on hemodialysis presented with symptoms of nausea and vomiting. A CT scan of the abdomen revealed rounded, hyperattenuating intraluminal foci throughout the colon, possibly coins or buttons (Figure 1). General surgery was consulted and opted for a watchful management approach as there was no perforation. Further investigation revealed that the patient had been swallowing his phosphate binders, sucroferric oxyhydroxide, whole rather than chewing them. Radiology confirmed that the coin-shaped anomalies detected on imaging matched the size and shape of these tablets. Subsequently, the tablets were recovered intact from the patient's stool. Discussion: Ingestion of foreign bodies can pose serious risks, necessitating prompt identification and management to prevent potentially life-threatening complications. It is imperative to differentiate such cases from instances of ingesting radio-opaque medications. The CHIPS mnemonic (chloral hydrate, heavy metals, iron, phenothiazines, and slow-release preparations) was developed to aid in identifying culprit medications. Sucroferric oxyhydroxide, a chewable iron-based phosphate binder, has negligible systemic absorption. Due to its insoluble iron content, unchewed sucroferric oxyhydroxide tablets appear as highly radio-opaque round objects on imaging. Understanding the properties and absorption mechanisms of such medications, coupled with thorough patient history-taking, can mitigate the need for invasive interventions and guide appropriate management strategies.