Clinical and urinary characteristics of urolithiasis in ulcerative colitis.

In a group of 112 patients with ulcerative colitis, eight patients (7.1%) developed the complication of urolithiasis. A higher incidence was found in those with total colitis (15.4%) and in postoperative patients (20%). The mean period between the onset of colitis and the initial urinary symptoms was 5.4 yr. All the analyzed stones contained oxalate and seven of eight patients had hyperoxaluria, which was believed to be one of the important lithogenic factors. Increased urinary Ca/Mg ratio, steroid, and sulfasalazine are suggested as the other lithogenic factors in patients with ulcerative colitis.