I'VE been away having my kidneys seen to.

I'm forever having my kidneys seen to. Since the age of 14 I've been plagued by kidney stones – some small, some big beasts ("staghorn") that have needed surgical removal. As a teenager and young adult the main problem was not the feeling of someone dragging a red hot poker around my innards, rather it was hanging out in urology with a bunch of grey-faced blokes over the age of 50. There's nothing a teenage girl likes more than to be told: "We'd normally see this in a middle-aged man. You're an unusual case."

I've been seeing the same consultant for the past two years. Being a gentleman, he still calls me Ms Stewart though I feel it's a waste to stand on ceremony with someone who could identify your internal organs from a line-up.

At our last meeting, before recent surgery, I pointed out I've now had stones cosying themselves inside my kidneys for half my life.

"Well, good news," he said, with the delight of the long-suffering sensing, at last, release. "The latest scans show stones only in the right-hand side. The left is clear!" Wait, what? Where have they gone? This has happened before: scans have shown stones and then I've gone for treatment to find they've already vanished. Then the next lot of scans show the stones are back. Personally, I think they're just camera shy but apparently that's not an appropriate medical diagnosis.

"You sound quite fond of them," my consultant says, bemused. I suppose I am. Sometimes when I walk I can feel twinges. My pregnant friend and I make quite a pair: she flinches when her baby kicks, I squirm when the kidney stones shift. We're both uncomfortable but at least her body's producing something socially acceptable.

On the surface of it recurrent kidney stones don't seem like much fun. Really, it's like keeping an old car running. Overall the vehicle's fine but some mornings it takes a little longer to get going and, just when you're puttering along nicely, something starts sticking. Or creaking. Or falls off. But you get used to the quirks of an old car, you get quite fond.

Life is full of confusion and insecurity. The only certainty in mine is the next appointment at hospital. Why would anyone want their life's one constant surgically removed?