I am on my 2nd dose of BCG. The first catheter and BCG I was fine.The second one they used a larger catheter and it hurt a lot more so if you feel more discomfort ask for a smaller tube. The second BCG made me so ill .it started about 4 hours after .I was violently shaking and fever hit 42. I took paracetamol and naproxen and after a few hours my temp started to drop but I still had headache feeling sick.this lasted all night and I eventually fell asleep at 5am and woke up at 2pm. I was ok when I woke and getting better each day.i would suggest before you go an hour. Before take paracetamol and ibuprofen to make your tolerance better to cope etc good luck.