Marijodon,
Sorry to hear of your husband's issue with treatment pain. Pain associated with bladder cancer treatment is an age old topic, and the development of a variety of ways to minimize that pain has made treatment more acceptable.
Can you or your husband, if he is willing and would like to talk about the problem with the group, describe in some detail the problem ? In all likelihood, people here will have suggestion on dealing with the problem. This site has been a great help to me.
The cause of pain is a bit unclear from your posting. 'Cystoscopy pain' is typically described much differently than 'treatment pain'. Does the troublesome pain occur during or after bladder inspection, during or after biopsy or is it during or after treatment with BCG or other intravesical therapy ?
As a last option, if the current doctor has run out of ideas, a second opinion focusing on making treatment possible may be in order.
I would hope that help can be found here.
Best,
Jack