Hi Jawink
I too have a very strong sense of smell, can even tell when someone has just woken up and changed into their day clothes without showering beforehand......!
I'm on Colazide which I think is the Australian name of Colazal. As I don't have any family jewels, can't say I've felt pain there ;)
I can smell when going to the toilet and/or on my skin a faint smell, but then again, I can smell different smells when on antibiotics (such as am on now) and also when on pred. I can tell when I can taper to a lower dose of pred as the smell on my skin and in the urine gets pretty intense. As you say, like a canary in a mine.
I've noticed with Colazide, I get skin discolouration/pigmentation on the neck and side of face. The higher the dose, the more noticeable it is. Am presently on 6 x 750mg daily so it looks like sun damage. Checked it out with a skin Dr and it is definitely pigmentation.
Cheers