Hello Graham and thanks for posting

I am sorry to hear about your situation and hope you don't have too long to find out how successful the BCG treatment has been.

Unfortunately BCG can cause the bladder to become irritated and this can lead to cystitis (inflammation of the bladder). Often this will resolve itself over time, especially once treatment has ended and hopefully will start to settle down soon.

Do make sure you are drinking plenty of water as this helps flush the bladder of any remaining debris. Also let your team know if you notice any further changes to the urine or any other new symptoms. 

Sometimes medications can be used to reduce the inflammation in the bladder and pain killers to ease any pain and discomfort if it is particularly bad but these won't always be needed.

I hope you know more soon about your situation and things start to improve for you.

Best wishes

Naomi