Abstract
BACKGROUND: Crohn's disease of the small intestine typically causes abdominal symptoms and nutritional problems, but renal consequences are rare. CASE PRESENTATION: We report a 70 year-old British Caucasian man with longstanding Crohn's disease of the small intestine complicated by multiple fibrotic strictures, who developed a rapid deterioration in his renal function around the same time as initiation of biologic therapy. Following investigation into the cause of his renal deterioration and eventually a renal biopsy, he was diagnosed with oxalate nephropathy leading to end-stage renal failure with creatinine peaking at 604 umol/l. The pathophysiology of enteric hyperoxaluria in Crohn's disease is discussed. CONCLUSION: Awareness of hyperoxaluria and potential oxalate nephrotoxicity in patients with small intestinal Crohn's and an intact colon should help clinicians advise such patients on dietary and fluid intake modification at an early stage.