Ten people sit smiling round the remnants of the feast, discussing everything from the latest avant-garde choice at the local Odeon to the latest avant-garde choice for No 10. But at least two of the diners will be suffering significant discomfort. In view of their lifestyles, this figure might easily be doubled to four.
One is probably a woman, shall we say a 32-year-old, high-flying public relations executive. She longs to undo her belt and release the torture she is inflicting on her bloated stomach: how embarrassing. Even worse, she has wind, but unlike the City banker/weekend rugby player opposite, she can hardly belch at the table. Belching is actually the least of his problems. He can feel his bowels moving and knows he is going to have to make a dash for the loo; he hopes the hosts have strong air freshener.
The host knows that the loo has air freshener: His problem is that he can't remember the last time he needed to use it. This meal has just thrown another couple of pounds of red meat with all the trimmings and another few pints of alcohol into his stomach to bubble away and ferment on top of the other meals he has not managed to excrete for the past four days.
Roll on a couple of hours; the party is breaking up. Our PR executive is embarrassed about standing up. Her black elastic body-stocking loves shaping itself mercilessly round unsightly bulges; she hopes the chair will creak to hide embarrassing noise from her tummy. Our sporting banker is praying that nobody decides to use the loo: there was air freshener, but it has been finished. The host just wants to go to bed and rest his vat of fermenting foods on the mattress.
Enter our fourth and final character: a successful media type. She hopes that the taxi company has fast drivers who know the back routes from Fulham to Islington: otherwise, it could mean 20 minutes with no loo to hand, just in case her bowels do spring into action.
This is not the start to Tom Sharpe's latest best seller on city lifestyles. The characters may be fictional, but they are all suffering from a very real affliction that affects one in five of the adult population: irritable bowel syndrome (IBS).
IBS is the most common disorder of the intestine, the part of the digestive tract extending from the exit of the stomach to the anus. It is not life-threatening, but for these 12 million sufferers it causes enough pain, discomfort and embarrassment to compromise the quality of life.
Some, with chronic diarrhoea, are so nervous about ensuring they have a toilet nearby that they become housebound. Some can never eat more than a few mouthfuls without feeling full or ill. Others are severely constipated. New statistics from the United States suggest that IBS may be second only to the common cold in causing time off work, and is costing industry millions of dollars.
Dr David Silk, who is leading one of the few research programmes into IBS at the Central Middlesex Hospital, London, believes the number of sufferers could be significantly higher than one in five.
"Victorian prudery still compromises many people's conversations with their doctors, let alone around the dinner table," he says. "I have no doubts that there are still many IBS sufferers unwilling to come out of the closet. People do not like talking about their bowels."
A world authority on clinical nutrition and intestinal function, Dr Silk has devoted his life to the human waste disposal unit and its malfunction.
"What people have to accept is that everyone from the Queen to the local tramp has the right to have reasonably regular and pain-free bowel movements,'' he says.
Accepting the bowels exist is the first step in tackling IBS. "If you do not have bowel movements, how can you have an irritable bowel syndrome? People need first to be able to say, `It is normal to crap and to fart' before they can say, `My crapping andmy farting are out of order, and it is distressing me'. If they do not, the psychological problems can be as devastating as anorexia or bulimia."
Dr Silk chooses his words with care: the crude terminology, in contrast to the quiet, cultured voice, is intended to shock. He believes doctors must accept some responsibility for the lack of awarenessof IBS. Many sufferers, he says, have been fobbed offwith talk of tummy problems being psychosomatic; the idea that IBS has psychological roots is, he says, a "persistent myth".
Other patients are advised to take a dose of Andrew's after a meal. IBS sufferers were also told to eat more fibre - now recognised by Dr Silk's team to aggravate the condition in some cases. IBS is thought to be due to a disturbance of involuntary muscle movements in the large intestine, which is why it affects the speed, smoothness and ease with which food passes through.
There are three main variants of the disorder: spastic colon, the most common, results in lower-abdominal pain so severe that it can double the sufferer up, as well as abdominal bloating; diarrhoea results in the need to rush to the loo six or eight times a day (some sufferers have lost their jobs because of their inability to travel) and can also cause weight loss and listlessness. Primary disorder of motility of the foregut (the upper part of the small intestine), the least researched type of IBS, canresult in feeling full after only a couple of mouthfuls of food, nausea and continual discomfort. Some symptoms can be alleviated with drugs or changes in diet and lifestyle but to date there is no cure.
Until recently, research consisted of tethering the patient to a variety of machines and monitors by a spaghetti junction of tubes and cables. The usefulness of this was limited because it could not monitor the patient's lifestyle and its effect on the digestive system. Today, it is possible to insert a microtube (3mm across), via the nose into the intestine.The tube, which can cause slight discomfort at the back of the throat, stays in place for 24 hours while the patient continues his or her normal routine.
Built into the tube are sensors that register and measure muscle contractions and pass this information to a small computer recorder worn on the patient's belt; intestinal movements can be monitored as the sufferer eats, drinks and makes merry.
Dr Silk's unit at the Central Middlesex is one of the few centres in the world to be carrying out this kind of research into the cause of IBS, without which, he points out, there can be no genuine cure.
His team at the hospital has already monitored 70 sufferers and is hoping to monitor more than 300 by July 1995. Once the research has been completed, he estimates it will take a further seven years to develop a cure. The total cost of the research programme is estmated at about £10m and funding it depends on public support. Dr Silk knows it will be a battle to raise the money: IBS is not life-threatening, nor does it affect children, and the subject of defecation is unlikely to be the beneficiary of a Women's Institute fund-raising luncheon in Tunbridge Wells.
Dr Silk, however, is hoping for support from Britain's 12 million sufferers. The first hurdle, he says is for more of those sufferers to come out of the closet.
"While people hide the problem from their doctors, friends, workmates and families their lives will continue to be compromised. Both the stress of suffering in silence and the lack of help will only aggravate the symptoms.''
So let us be brave: at the next stylish dinner party, instead of discussing the respective merits of John Major and Tony Blair or the latest exhibition at the Tate, let's really get down to the basics.
Donations to Dr Silk's research programme should be sent to the IBS Appeal, Central Middlesex Hospital NHS Trust, Acton Lane, London NW10 7NS. Cheques made out to IBS Appeal.