Namita, you are a long way from asking BCG questions!!!
First the doctor has to determine IF you have cancer. During the cystoscopy he will look at the inside of the bladder with a very small, lighted camera. IF he sees suspicious areas he will most likely schedule you for a TURB (transurethral resection of the bladder) where he will do a similar procedure while you are under general anesthesia and take a lot of samples of the bladder tissue to send to a pathologist for analysis. Only after he has the pathologist's report will you know for sure whether or not cancer is present, if it has remained localized or spread into the other layers, and how aggressive it might be.
Questions you might want to ask at this point (after the cystoscopy when he has had a chance to look at the bladder): a. what did you see and what are your thoughts; b. what is the next step (TURB?) c. what other things could be causing my symptoms?
IF you have bladder cancer, depending on the pathologist's report of its characteristics, the urologist will recommend a course of action. If it is low grade he may recommend nothing more than a close watch with cystoscopy every three months. If it is high grade, BCG may be indicated (and THEN you can learn all about it!!).
Please let us know how your cystoscopy goes!!
Sara Anne