Clinical manifestations of calcium oxalate monohydrate and dihydrate urolithiasis

We studied retrospectively 155 patients with calcium oxalate urolithiasis. The patients were divided into 3 groups: 1) those with calcium oxalate monohydrate, 2) those with calcium oxalate dihydrate and 3) those with mixed calcium oxalate monohydrate and dihydrate. Various differences were noted between patients with calcium oxalate monohydrate and those with calcium oxalate dihydrate, with respect to stone characteristics, spontaneous passage of stones, stone recurrence and multiple occurrence. Most important, we noted that patients with calcium oxalate dihydrate had more stone recurrences than patients with calcium oxalate monohydrate.