I think the answer to that is that the nurse would use a dipstick, which changes colour if there is an infection, but doesn't show what the infection is.
If the stick does change colour, they send a sample to the lab for culture, so that they can get the right antibiotic.
Thanks Hazel, I didn't realise that. But the first test came back negative and we had to wait 4 days to hear that.
The discharge notes said it was an unknown infection. My guess is that it was the wound from the biopsy, which thankfully has shown nothing sinister.
My Dad is fine now he is home. No incontinence and today he decided, without prompting, to take the dog for a walk. Just as well as after he got home it poured down all day. I should know as I went for a 6 mile walk, as it is only 5 months until my Sahara trek for AS, and I got wet through. Not likely to be a problem in the desert.