Iron bezoar retained in colon despite 3 days of whole bowel irrigation

Concretion formation is a documented complication of large iron ingestions. The generally accepted treatment is supportive care, whole bowel irrigation, and intravenous deferoxamine for systemic toxicity. Laparotomy and gastrotomy have also been used in patients with a high iron burden and bezoar formation. Though experiments suggest that iron is poorly absorbed in the colon, there are no case reports of iron overdose without systemic toxicity, despite a retained colonic bezoar. We report the case of a 16-month-old who presented to an Emergency Department 19 h after an iron ingestion. Initial laboratory studies revealed an anion gap of 14 mEq/L, and a 20 h serum iron concentration of 429 mcg/dL. An abdominal radiograph revealed multiple pills throughout the stomach and small bowel; whole bowel irrigation was initiated. Deferoxamine was administered at 10 mg/kg/h and then stopped when the serum iron level reached 27 mcg/dL, 36 h later. At this time, the abdominal radiograph showed an iron bezoar remaining in the ascending colon despite a clear rectal effluent from whole bowel irrigation. Despite whole bowel irrigation over the next 36 h, the iron bezoar was not removed and actually migrated proximally in the colon. Treatment was stopped on the third day and a normal diet was instituted with prompt passage of the bezoar.