Tuesday
I suppose it's the down side to being one of Britain's elite corps of semi- professional hypochondriacs, but tonight at dinner a slight acquaintance speared an artichoke heart into her mouth, looked me in the eye and said: "By the way, Matthew, how is your bottom?" After the momentary shock had worn off a more acute sense of amazement struck when the answer came to me. "Funny you should ask, but it's absolutely fine," I said very slowly, a little punch drunk from the unfamiliarity of the sentiment. "Never been better."

Wednesday
Awake nervy and distrait after a typically troubled night, feeling threatened by some nebulous foe. For many years, as I often had cause to observe, my bowels have been not so much irritable as psychotic, perhaps borderline sociopathic. As for haemorrhoids, all I will say is that if Anusol had a frequent user scheme, I might be on some Caribbean beach now at the company's expense. At the moment, however, I am weighed down by the knowledge that merely by noting the dearth of pain - something I ascribe to a new, healthy diet - is a stamped self-addressed invitation to fate that fate is unlikely to turn down.

Thursday
The RSVP envelope arrived by first post. The pile is tucked away about a quarter inch up the rectum, on the right hand side. It throbs a little.

Friday
The pile is unchanged, and in a stable condition - certainly more stable than me. Yet there is nothing new about this awesome psychosomatic power to create symptoms. Once, when I was 20 and convinced that I required a new heart, I spontaneously developed a water swelling or oedema on the left ankle - something I had no conscious idea was a classic symptom of coronary disease. By this standard, a pile is nothing.

Saturday
The pile has doubled in size and in pain overnight. "Oh for God's sakes," says Rebecca when I update her, "if it's that bad why don't you call Sarah and pop round to her emergency surgery?" The truth is that I can't... I can no longer consult my personal physician Dr Sarah Jarvis about any matter that requires the donning of latex gloves. We have simply broken bread together too often for internal examinations to pass in the cheery, matter of fact, nothing-more- natural-in-the-world manner of old.

Sunday
While she is preparing the traditional Sunday lunch (I doubt there's a home cook in the country who can heat up a quarter pounder with cheese and large fries like my wife), Rebecca's patience with my moaning runs dry and irritably she tosses off a psychological theory. "If it was thinking about the absence of anything wrong that brought on the piles (that plural is correct; the second arrived this morning), why don't you find something else that's all right to worry about and they might go away?"

It sounds crazy, but what harm can it do? "OK," I say, "but what?" "I don't know, something inanimate. The mobile phone? Or the car had its service last week, and that's going well? Or the microwave? Oh my God, the micro..." While she is removing the melted polystyrene boxes with a pair of plastic tongs, I head for the phone to call Domino's.

Monday
Rebecca's mental trick seems to have worked. Yesterday evening, I transferred the object of my neurosing to a different area, and although both piles remain, the original is smaller and has ceased to throb, while Johnny Come Lately has shrunk even more markedly. "Do you know, I think you could be onto something," I tell Rebecca when I ring from the mobile this evening. "I'll take rooms in Harley Street," she says, almost pleasantly. "By the way, I thought I'd get fish and chips for supper. How long do you think you'll be?" "I don't know," I tell her. "The AA said they could be anything up to an hour and a half."