Mercury - stomatitis, abdominal pain, nausea and vomiting, and explosive, bloody diarrhea.
Iron - vomitting, hematemesis, diarrhea, hypotension, and metabolic acidosis
Arsenic - skeletal muscle cramps, abdominal pain, watery diarrhea, vomiting
Lead - headache, abdominal pain, constipation, coma, convulsions
Selenium - garlic breath, hair loss, skin depigmentation, abnormal nail growth, fatigue
Source: NMS review for USMLE Step 2 Ck