Vicarious excretion of contrast medium in patients without azotemia.

Although excretion of urographic iodinated contrast agents via the biliary and gastrointestinal tract is not uncommon in patients with renal insufficiency, such vicarious excretion is unusual in the presence of normal renal function. The observation of such vicarious excretion in 2 patients with acute unilateral ureteral obstruction and no azotemia is reported in conjunction with review of the appropriate literature and suggestion of possible etiologies.