Abstract
Inflammatory bowel diseases are typically accompanied by diarrhoea and malabsorption, both of which are predispos-ing factors for the formation of renal calculi. In patients who have not undergone bowel surgery the prevalence of urolithiasis has ranged from 1.5% to 5%, but after surgery stone prevalence can increase to up to 16%.
Enteric hyperoxaluria is a frequent complication of inflammatory bowel diseases, ileal resection and Roux-En-Y gastric bypass and is a recognised cause of nephrolithiasis and nephrocalcinosis. The excess of oxalate is primarily excreted by the kidneys.
Increased urinary excretion of oxalate results in urinary calcium oxalate supersaturation, leading to crystal aggregation, urolithiasis, and/ or nephrocalcinosis. Prevention of oxalate lithiasis includes high fluid intake, prescription of oral citrate and magnesium, calcium supplement, nutritionally balanced low-oxalate low-fat diet and also biological manipulation of intestinal flora (Oxalobacter formigenes, Bifidobacterium lactis, etc.).
New therapeutic approaches to patients with inflammatory bowel diseases have completely changed the natural history of these diseases. Whether this has changed the prevalence and risk factors for urinary calculi in patients with inflammatory bowel diseases is still unknown.