Yes, passing of some tissue IS normal, but when it becomes painful the urologist should have some idea of something to help. I hope your husband discusses this on his next appointment and persists in explaining that this is NOT acceptable to him.
As for the dosage, it is interesting that there is no "scientific" rationale for the dosage used. My understanding is that this is what was available when it was first tried as an infusion for bladder cancer; it worked, so that is what is used.
When problems arise, it IS common to reduce the dosage. I developed what is called "BCG-cystitis".....irritation of the bladder lining from BCG...and often needed to skip a treatment since they do not use BCG if there is anything like an open sore on the bladder lining. By the time I finished my two years of treatment I was on 1/3 the initial dose. It appears that reduced doses, especially after a number of treatments, is NOT less effective.
Some patients become so uncomfortable that they discontinue BCG altogether after a number of doses. These patients still benefit from the ones that they have had. This is a decision that your husband may need to make.
Sara Anne