Abstract
Hyperammonaemia causing encephalopathy and coma is a recognized but rare cause of altered mental status in patients with urinary diversions, most commonly associated with ureterosigmoidostomy although also with ileal conduits. We describe the case of a 41-year-old lady with an ileal conduit who developed severe hyperchloraemic metabolic acidosis and associated hyperammonaemia. This led to a significant decrease in her Glasgow Coma Score such that she required Intensive Therapy Unit management. We review the current literature on this condition, discussing its aetiology and management.