57 yr old male. coumadin patient. Hematuria since last friday. went away for part of sat., back on sun., and now much less. Recent ceftin use for URI, stopped on Sun. Sonogram of kidneys, liver, spleen and bladder negative. CT of abdomen and pelvic area all negative. Cystoscopy, pathologist exam of urine and PSA are next. Your ideas on the cause of the hematuria?