Although the differential diagnosis for abdominal pain is extremely broad, given her history (and that this is a toxicology website), iron toxicity is the most likely culprit.

Iron toxicity occurs in five stages:

Stage 1 (0-6 hours): Abdominal pain, vomiting, and diarrhea.
Stage 2 (6-24 hours): Latent stage; GI symptoms may improve while the organ damage and metabolic acidosis worsens. Note: This stage may not always occur.
Stage 3 (6-48 hours): Systemic toxicity; Symptoms range from return of GI symptoms to multi-organ failure with seizures and/or coma.
Stage 4 (2-5 days): Fulminant liver failure.
Stage 5 (4-6 weeks): Delayed effects of mucosal injury (rare) causing bowel obstruction due to Iron’s corrosive damage to the stomach/intestine.

In general…

Clinical Effects	Elemental Iron Dose	Serum Iron Concentration
Non-Toxic/Mild Ingestion	<20 mg/kg	<300 mcg/dL
Moderate Toxicity	20-60 mg/kg	300-500 mcg/dL
Severe Toxicity	>60 mg/kg	>500 mcg/dL

Note: FeSO4 325 mg = 65 mg elemental Iron

Consider whole bowel irrigation if there was a significant ingestion or increasing serum iron levels. Activated charcoal has not been shown to improve outcomes as it poorly adsorbs ions such as Iron. Otherwise, fluid resuscitation and supportive care are the initial interventions.

Consider deferoxamine if peak Fe levels are > 500 mcg/dL (regardless of whether they are downtrending), metabolic acidosis is present, or there are signs of systemic toxicity. The initial dose is 5 mg/kg/hr IV titrated up (as tolerated) to 15 mg/kg/hr (Max Dose: 1 g/hr) with no more than 6 g given during the first 24 hours. Side effects include hypotension (assoc with fast administration rates), red (‘vin rosé’) urine, pulmonary toxicity (if given for > 24 hours), and risk of Yersinia bacteremia. Deferoxamine is safe in pregnancy. Deferoxamine should be stopped when the patient shows signs of clinical recovery with the guidance of a regional poison control center.

Obtain an initial Iron level (and consider serial Iron levels if you suspect a significant ingestion). Also check a venous blood gas (for pH), complete blood count, electrolytes, kidney and liver function tests, and coagulation factors. Consider abdominal x-rays.

Note: Not all iron supplements are radiopaque, so a negative x-ray does NOT rule out ingestion.

Patients with mild ingestions and who remain minimally symptomatic (mild nausea and vomiting) may be discharged home or transferred to psychiatry after six hours of observation. All other patients should be admitted to the hospital. Anyone with significant ingestion, increasing levels, and/or given Deferoxamine should be considered for admission to the ICU.