If there is still blood in the urine, the doctors have to be sure there isn't something else going on. In someone who passed a stone, the most likely thing would be that the stone has just moved, and maybe there is still some bleeding going on. But in a smoker, it would be good thing to look. If there is bladder cancer, it isn't that hard to treat 70% of the time. Superficial bladder cancer is generally treated by a series of instillations of interferon or chemotherapy drugs into the bladder. Cure is frequent, and even without cure, it can often be managed without a lot of trouble. Polyps, either cancerous or non-cancerous, might also be bleeding. If this is the case, they need to be removed. A cystoscopy is a relatively easy procedure and should answer the questions. I know, because I've had several.