The toilet. Perfect sanctuary. Lock the door, park your bum, and leave the world behind. Sit on the throne, master of your universe. Fag in hand, paper on knee, louchely graffiti'd door ahead of you, buttocks squeezed - what could be better?

Toilet time, my favourite time of the day. I always tell my colleagues when it's time to go. I used to get weird looks - disapproving grunts and murmurs. But now they understand. I just wanted to know there was always a little room where you could lock yourself away and contemplate, reinvigorate yourself. The toilet has long been my inspiration. Most of the great headlines are dreamed up in the loo, many life-changing strategies are devised in there. When Blair and Bush talk about thinking out of the box, they mean the thunderbox.

So I'm off to the loo. It's like packing for a holiday. And I always have to return for things I've forgotten. Cigarettes (a must in the non-smoking office), a flow chart so you can get on with a bit of work, a jumper in case the weather changes while you are away. And a book, a newspaper, a magazine. I like reading women's mags on the khazi - stories about how bad I am in bed are a particular favourite; somehow if you do it in public you have to apologise for it. There should always be a stack of magazines to the side of the bowl, and Cosmopolitan should definitely be among them.

I know I'm not alone. We love to read on the bog, especially men. A survey last week by the Imperial Cancer Research Fund (ICRF) found that 49% of men read on the toilet, compared to a slightly disappointing 26% of women. Most men read newspapers, 14% catch up on current afairs, 4% even scan their bills for inspiration.

But if you confine your toilet trips to this season's new lipstick colours, a splash and a wipe, you could be missing something important. The same study found that only 44% of us bother to cast a quick look behind before we pull up and zip up. Which is rather silly. If we paid a little more attention to our crap, according to Dr Wendy Atkins, deputy director of the colo-rectal cancer unit at St Mark's hospital in London, we might just save our lives.

Bowel cancer is the second biggest cancer killer in the UK, next only to lung cancer. In 1998, 17,000 people died of it. Yet it is one of the most treatable forms of the disease - 90% of cases can be stopped in their tracks if caught at the right stage.

The most important thing is noticing the symptoms early. "If you just leap off the loo without having a quick look behind, you might miss it," says Atkins. What you're looking for is blood. Red blood, or clotted blood, not the little spots of blood you might get if you have piles after spending too much time reading on the bog in the first place. Your number twos are also likely to be "more loose", and you might find, says Atkins, that your toilet habits change. By which she means, if you get through the Brothers Karamazov in a week due to the number of times you need to visit the little room, it might also be a sign of something wrong downstairs.

If you have both symptoms - blood in your stools and a touch of the runs - it's time to take it seriously, says Atkins, particularly if you are over 50. And particularly if you have a family history of the disease. And particularly - rather unfortunate, this - if you smoke. "The chance of having a polyp (early stage tumour) is much more likely if you are a smoker," says Atkins. Which makes eminent sense, but rather pisses on one of life's great pleasures.

Needless to say it is men who are especially useless at dealing with their crap. We are, according to Atkins, particularly bad at taking note of something murky in the bowl, hoping instead that it will just go away. It is that great British disease again: embarrassment. But if you see blood more than once, and don't know of anything else that might be causing it, get along to the GP. Better than dying for a crap, so to speak.

Better still, once you have turned round to check that healthy little turd, why not throw the packet of fags down the loo as well. Less chance of cancer, more reading time.