D-DAY MINUS ONE
I go to Leor Cohen’s Welbeck Clinic (which is actually a couple of rooms in a private house off the Finchley Road) to receive my instructions: organic everything, only distilled water, 23 vitamin supplements four times a day, special cleansing drinks five times a day, and a “liver flush” on waking. I must come for daily colonic irrigation sessions to flush away the layers of glue-like crud encrusting my colon. I must skin brush morning and evening. I must exercise daily. I receive a carrier bag of pills and powders together with a 15 page instruction sheet.

Clearly, this is not going to be simple. Because I’ve been preparing for weeks – swallowing supplements, skin-brushing, juicing, going for fortnightly colonics – the procedure itself holds no surprises. I undress, don a blue paper hospital gown and lie on the bed, complete with patchwork blanket and pillows, while Leor inserts a two-way metal valve into my bottom. I never quite get over the initial embarrassment of this, but once the cringe-making moment is over, an easy familiarity builds.

Certainly, we share a mutual fascination as we watch 15 gallons of water disappear in and out of my body via a clear stretch of tubing. As we wait for the debris of decades to disengage itself from the sides of my bowel, Leor massages my abdomen and we talk about everything and anything – but mainly what’s just emerged. Since, even in these free and easy times, defecation remains otherwise conversationally off-limits, I rather relish the chance to discuss this most private of bodily functions.

I soon discover there’s no chance of keeping any dietary transgressions from Leor. He’s young, engaging and personable, but no fool. In fact, he’s so good at spotting what I’ve been eating, it’s rather like going on an anal safari. Today he identifies incompletely digested potato skins from the baked potatoes we had for lunch yesterday. He also has an uncanny way of predicting shopping what’s about to come through the tube, and is always pleased to see it. For my own part, I find being congratulated on producing bowel movements most peculiar. No one’s done that since I was perched on a potty aged one-and-a-half.

D-DAY
The surprising thing is that I’m not at all hungry. I go to my six-year-old godson’s birthday tea and, uncharacteristically, don’t want any of the sickly spread. In fact, feel so full, I try to negotiate a lower juice intake with Leor. He wants me to drink one fluid ounce per pound of my total body weight in juice each day – that’s more than a gallon.

So much for all that spare time I think I’m going to have while everyone else is shopping
cooking, eating, washing up and planning the next meal. To be fair, Leor urged me to take the week off. But with four children between the ages of three and 11 at three different schools, a new puppy and an immovable deadline next week, a holiday’s unthinkable. Even with my long-suffering nanny, Katty, and hands-on husband Charlie, it’s clear the rest of my life will have to go on hold. Every half-hour I’m scrubbing and chopping vegetables and pounding them through then juicer; or swallowing supplements, or blending an unbelievably disgusting “cleansing cocktails”, or skin brushing to rid my skin of surface toxins, or exercising, or undergoing my daily colonic. Or washing up all the endless juicer and blender parts. Or going out shopping for more supplies… Or… Or… Or...

D-DAY PLUS ONE
I’m supposed to start detoxing in earnest today. In his cult American book The Tao Of Health, Sex and Longevity, Daniel Reid claims that it takes at least 24 hours for the body to start pouring toxins into the blood stream for elimination, soon after which it will be carrying up to 10 times its normal load. “You will feel weak, fatigued, stiff, light-headed and perhaps a bit nauseous, much like a heavy hangover,” he promises. But no. No hunger, or headache, or any of the other “h” for horrible things that are supposed to kick in. Instead, I’m full of energy (and juice) and not remotely bad-tempered.

It doesn’t take me long to realize that what’s really required for this programme is not willpower but formidable organizational skills. Leaving the house for a couple of hours on, say, the school run, demands 20 minutes of filling Thermos flasks with juice, to which ice cubes have been added (distilled water, natch), collecting together mini bottles of the two cleaning drinks, plus little polythene bags of vitamins and the “drawing powders”.

D-DAY PLUS TWO
Where, oh where are my detox symptoms? I’d like a little debilitation, light-headedness, a hunger pang at least. But even the smell of frying bacon fails to get the salivary juices going. I don’t get any of that hollow emptiness on associates with hunger, either, probably because I’ve got so much juice sloshing around my stomach, together with the drawing powder which apparently swells to 40 times its volume. I feel full all the time.

When I go out running with my personal trainer Duncan Stroud and clock two-and-a-half miles with ease, he is impressed. But I am vaguely worried. Aren’t supposed to be feeling terrible? Is the detox working? Everything I read encourages me to believe a dramatic response is desirable, but I console myself by concluding that these detox merchants want it both ways. If you feel great, they say “goood, goood” and take the credit for it; if you are feeling low and lousy, they say “goood, goood” and tell you you’re undergoing “a healing crisis”.

Healing crises notwithstanding, Leor swears I am thinner. I shrug. My trousers still feel uncomfortably tight since my stomach is bloated by gallons of juice and slime. But later, shopping with my daughter in Nicole Farhi in Hampstead, I try on a sarong and inquire about the size, which is note on the label. “Oh, sorry,” says he sales assistant. “They’re all 10s. I’ll just nip to the storeroom and get an eight.” An eight? I was a size 14 this morning.

D-DAY PLUS THREE
Hooray! I wake up feeling… skinny. Examining myself in the mirror, I can see something that looks suspiciously like a hipbone beneath the flesh of my abdomen. I’m still not hungry and I’m still not hungry and I’m finally allowed fruit juices. Although apparently less cleansing and more calorific than celery, beetroot and carrot, they are sweet and delicious. I savour orange and pineapple, black grape mixed with apple and pear, and mango and passion fruit.

Even though my weight is up a pound on yesterdays, there’s a mini avalanche through the tube – apparently the volume will increase every day as years of impacted residues detach themselves from my colon. To inspire me, Leor shows me some astonishing pictures of what has come out of the colons of fasting subjects: long, contorted stretches of “mucoid plaque” which have been stuck in the folds of colons for decades and that look like black rubber – some are up to two-feet long. I can’t believe I’m harbouring such gunk, but Leor tells me that the average Western meat-eater’s colon contains between five and 10 pounds of impacted waste.

What’s stranger than strange is that, after a few days the blackly gelatinous brew is beginning to appear almost acceptable. But I’m dead suspicious. I have a hunch that the primordial slims is solidifying and expanding in my guts, and that’s what’s coming out, with the black colour caused by the charcoal in the drawing powder, rather than any age-old putrefied waste.

Another extraordinary thing: I’m beginning to find the sessions rather relaxing. This afternoon (my seventh time) I nearly dozed off, and would have done if I hadn’t been so worried about missing something vital in the tube.

D-DAY PLUS FOUR
It’s Saturday, and Leor’s day off. I could do with one, too. It’s not that I’m longing for food, just liberation from the tyranny of the juicing timetable. If you think fasting equals freedom from food, and the chance to focus one’s mind on higher things forget it. Keeping my intake up dominates every waking moment. I don’t have time for anything or anyone else. The kids are getting fed up, as is Charlie, for whom the novelty of self-catering has worn off. “What’s that horrid smell?” grimaces five-year-old Clemmine at breakfast (croissants and pains au chocolat for them; spinach, courgette and cucumber juice for me). “Yuck, it stinks.”

Even with the colonic hour out of my day, it’s hard to stick to schedule. The day starts well enough at 6am with a four mile run in the spring sunshine, but goes to pieces later. Now it’s late evening and suddenly I’m four hours behind.

Although I’ve felt perfectly normal all day. I’m feeling cold, light-headed and nauseated and the pills make me want to gag. When Feddie, the two-year-old, playing at mixing my drinks accidentally ingest a teaspoon of clay and begins retching, I panic that it will start solidifying and obstruct his system. I am about to ring casualty when Charlie returns home and laughs, bringing back some sort of perspective.

I long for bed but cannot go because I’m so far behind schedule: I still have to my fourth round of juices, followed, at least one-and-a-half hours later, by the primeval slime and, at a decent interval after that, the aloe vera, which must be taken on a empty stomach. At this rate, it’s going to be 2am before I finally turn in.

I have decided if I cannot comfort-eat, at least I shall comfort sleep. I have a warm bath and fill a hot-water bottle. But the luxury of a long sleep is denied me – I have so much fluid inside me that I have to get up twice in the night.

D-DAY PLUS FIVE
Another day of total subjugation to the schedule. Charlie and I are like the weather-clock people – in and out of the house, ferrying everybody to and from birthday parties and social engagements – except that wherever I go, my wicker basket and Thermos flasks and mini Evian bottles go, too. At least my spirits have recovered from last night’s low, helped, no doubt-take when I come in wearing skinny black jeans and poloneck (which slice inches off the silhouette, anyway). He tells me I look 20 years again. It’s an observation that, I have to say, has yet to strike my husband.

This evening, I telephone my sister-in-law, Annie, a physiotherapist. I haven’t see her for a month, and when I divulge what I’m up to she’s full of cautionary tales of clients who became hooked on colonics and then found that their bowels refused to shift for themselves for ever after. Since this is one of the areas where my body has always performed competently, I become just a touch apprehensive as to what might happen when I break the fast.

D-DAY PLUS SIX
Wake up sizzling with energy despite little sleep. Archie tells me I look a little thinner, Romily is very encouraging and Charlie just grunts that Leor is a grade-A sadist. I would be an excellent candidate for living in a totalitarian fascist state, he continues, as I’m so good at obeying orders.

The weird thing is that as the end of this extraordinary ordeal comes into sight, I start feeling hungry for the first time. Food at last regains its appeal and aroma, as though my senses are coming out of hibernation. When I see Leor for my final colonic, I’ve lost half a stone and my stomach is quite flat. My blood pressure has dropped, too. I feel purged, finished. When Leor tells me he’s really please with the results “considering it’s my first time”, I realize he’s already thinking about doing another one. Another one? Now way!