Oral Iron and Coffee-Ground Emesis
Oral iron supplements can be associated with coffee-ground emesis in the setting of iron-induced upper gastrointestinal mucosal injury. [1] Coffee-ground emesis represents dark brown, granular material that resembles coffee grounds and often reflects coagulated blood from an upper gastrointestinal bleed. [2]
Mechanisms Linking Oral Iron to Coffee-Ground Appearance
Iron can cause gastrointestinal irritation that may include nausea and vomiting. [3] Gastric siderosis or iron pill gastritis has been reported in association with coffee-ground emesis, along with other manifestations such as melena. [1] Iron in the gastrointestinal tract can also contribute to black discoloration, which can be confused with bleeding presentations. [4]
Evidence From Clinical Reports
A case report of oral ferrous sulfate–associated ischemic-type gastritis described presentation with melena and coffee-ground emesis after initiating oral iron therapy. [5] A case report of gastric siderosis due to oral ferrous sulfate described coffee-ground emesis as a possible associated symptom. [1]
Distinguishing Iron Effects From Upper GI Bleeding
Coffee-ground emesis is classically attributed to coagulated blood from upper gastrointestinal bleeding. [2] Vomiting that appears like coffee grounds should be treated as potentially significant until other causes are evaluated. [2]
Clinical Urgency
Coffee-ground emesis is considered a medical emergency presentation because it can reflect upper gastrointestinal bleeding. [6]
Practical Safety Considerations
Immediate discontinuation of the suspected offending oral iron dose is typically considered when iron pill gastritis or iron-associated mucosal injury is suspected in clinical practice. [5] Assessment for upper gastrointestinal bleeding is clinically indicated when coffee-ground emesis occurs, regardless of concurrent iron therapy. [2]
When Oral Iron-Related GI Symptoms Are Likely
Nausea and vomiting are recognized adverse effects of high-dose or ongoing oral iron therapy. [3] Isolated emesis after iron ingestion without blood-appearing material is more consistent with medication intolerance rather than coffee-ground emesis from bleeding. [2]
Bottom-Line Clinical Interpretation
Oral iron supplements can cause GI adverse effects and have been linked to coffee-ground emesis in case reports, but coffee-ground emesis should be treated as possible upper gastrointestinal bleeding until evaluated. [1][2]