Welcome to the Forum!!
I assume that you have been diagnosed with CIS (short for carcinoma in situ). This is a high grade form of bladder cancer that appears sort of like a rash on the bladder lining rather than a solid lumpy tumor. High grade means that it has the potential to spread, which is why BCG is almost always used to treat it ASAP.
BCG can be very effective in the treatment of CIS.....that is the route that I took and I am fully healthy eight years out!
Your urologist is correct in that the side effects do increase as the treatment goes on. BCG is a modified tuberculosis bacterium that was developed many many years ago as a safe inoculation for children to try to prevent TB. In bladder cancer it is used to stir up the immune system in the bladder lining so that it attacks any cancer cells that are present. As the immune system gears up, your body will feel more side effects. The usual are bleeding, urinary urgency, burning, and fatigue. THESE SHOW THAT THE BCG IS WORKING! While they can be annoying, these side effects are nothing compared to those that people who must have systemic chemotherapy go through. As your treatment goes on, if the side effects become too much, the dose of BCG can be significantly reduced....as low as 10% of the initial dose in some cases. By the time I was through with my initial 6 weeks of treatment, and the two years of maintenance treatment, I was down to 1/3 the initial dose.
You will do very well, I am sure. There is a LOT of information about others' experiences with BCG in the material on this Forum. For example, we have archived a lot of posts at the top of the heading "Non-Invasive". You can also used the search function at the very top of this page.
Good luck to you. You are on the right path.
Sara Anne