Filling defects in small bowel urinary conduits

Radiographic evaluation of patients with urinary diversion by small bowel conduit includes excretory urography, loopography, and, if necessary, percutaneous pyelography. Five patients with discrete filling defects in their conduits are discussed. These defects represented stones (two cases), antirefluxing ureteral nipples, metastatic bladder carcinoma, and a 'turn-in' loop construction defect. While the nature of loop filling defects can often be discerned by radiographic studies and a knowledge of the conduit construction technique, endoscopic biopsy may occasionally be necessary for definitive diagnosis.