Acute intermittent porphyria

DDx

Acute abdominal pain due to other causes, e.g., appendicitis, peptic ulcer disease, cholecystitis, diverticulitis, ruptured ectopic pregnancy, familial Mediterranean fever
Polyneuropathy due to other causes
Guillain-Barré syndrome
Lead or other heavy metal poisoning
Psychosis due to other causes
SIADH due to other causes
Dark urine due to other causes, e.g., alkaptonuria