'It's a gut thing'

It's a long-standing joke with my family and close friends that I'll always be the first to suss out the toilet facilities anywhere I visit, be it a cinema, hotel, at a beach or even a friend's house. This isn't some morbid fascination with ceramic, or even a nosy curiosity about other people's bathroom decor. Rather, it's born out of a necessity to familiarise myself with my surroundings just in case my irritable bowel syndrome (IBS) strikes.

IBS has become such a part of my life that I'm not sure exactly when I started suffering from it. I can't remember a time when my digestive tract didn't make embarrassing gurgling noises – and not just through hunger – or when I wouldn't have a sudden and desperate urge to visit the toilet. I've since realised that these are both common symptoms of IBS.

I didn't experience any real pain or receive a diagnosis of IBS, however, until my first term at university. I was reaching into a cupboard when suddenly I was gripped by a sharp, penetrating pain in my left side, which left me doubled-over and unable to move. The campus doctor told me that I probably had something called "irritable bowel syndrome" bought on by stress. He packed me off to the chemist with a prescription for peppermint-oil capsules and some vague advice to avoid eating too much meat and increase my fibre uptake. At the time, I couldn't really find much information (or at least not discreetly) about this "disease", and I was highly embarrassed that I had something wrong with my bowels. I didn't take the peppermint-oil capsules for long – they caused a burning sensation in my chest about 20 minutes after taking them, not to mention recurrent peppermint-flavoured burps. I did, however, become vegetarian, thus reducing my meat intake to zero. Although I haven't to this day suffered such severe pain again, I have subsequently had bouts of constipation, painful bloating and diarrhoea.

About two years ago, my symptoms escalated to the point where I was forced to visit my new GP – the first time since being "diagnosed" that I'd mentioned my IBS to a doctor. To my relief, she regarded my symptoms as serious enough to warrant a proper investigation and organised for stool and blood tests, and for a flexible sigmoidoscopy (an investigation of the bowel). After one of the most invasive procedures I've ever had to endure, I was "properly" diagnosed with IBS in the absence of anything more serious being found. The consultant asked me, "Are you a tidy person?" and when I answered yes, told me that IBS was probably therefore due to my "stressed" nature and that I could improve my symptoms simply by reducing my fibre intake. At the hospital, I had been curious to see a waiting room full of people registered for the same procedure, and for the first time realised that I wasn't alone in my problem. Far from it: IBS is surprisingly common, with a third of the population affected at some time or other, about two thirds of them women.

As the name suggests, it isn't a disease, but a syndrome, recognised by a variety of symptoms, the nature and severity of which vary considerably between sufferers. In 1992, a group of bowel experts put together a description of the characteristic symptoms of IBS. These include abdominal discomfort or pain that is relieved by a bowel motion, and/or associated with a change in the frequency of bowel motion, and/or associated with a change in the consistency of stools. Additional symptoms that confirm IBS may include bloating and distension; more than three stools a day or less than three a week; erratic and/or unsatisfactory bowel motions; urgency; mucus in the stool; and nausea or loss of appetite. If patients have suffered some or all of these symptoms for at least 12 weeks in the preceding 12 months, with recurrence, they are said to be suffering with IBS. Symptoms may be constipation-dominant or diarrhoea-dominant, or, as in my case, a mixture of both. Although IBS is often chronic – once you've got it, it will always be there – symptoms can change over time, with IBS-free periods following spells of severe symptoms.

Amazingly, although about one person in five frequently suffers IBS symptoms, relatively little is known about it and diagnosis is usually by a process of elimination of other, more serious diseases. Although IBS is known not to be life threatening, theories about what causes the symptoms vary according to whom you ask. But all theories point towards an increased sensitivity in the gut, although what triggers this remains somewhat unclear. Popular and frequently documented ideas are that certain people are more susceptible following a bout of food poisoning, a radical dietary change or stressful life events.

In researching IBS, I've realised that I'm very lucky: although my IBS is often on my mind, and occasionally has been pretty uncomfortable, I haven't had symptoms so severe that my everyday life has been disrupted and I have never missed a day of work or study through IBS-related problems. Some people have symptoms so terrible that absence from work is commonplace and even a trip to the shops can cause problems.

Carol Sinclair, the author of The New IBS Low-Starch Diet, found that her IBS symptoms worsened as she grew older, from her childhood through her teens and into adulthood. "At their worst, my symptoms left me in incredible pain every night and frequently even in the daytime," she explained. It was at this point, in 1986, when bloating and gut pain were making her life a misery, that Sinclair stumbled across a television documentary that claimed that excluding wheat from the diet could eliminate IBS symptoms. After removing wheat flour, whole grains and wheat bran from her diet, Sinclair found that her symptoms dramatically improved.

Subsequent exclusion of all starch from her diet has left Sinclair completely symptom-free, and her book was written to help others with IBS. IBS symptoms vary from person to person, but she has received numerous letters from sufferers thanking her for the difference that the low-starch diet has made to their lives. She believes that research should focus more on physiological aspects of IBS, rather than assuming that it isa stress-related personality problem, as happened in my case. "There are so many people wasting time on studies into IBS personalities," she says, "when it's clear – it certainly was in my case – that IBS symptoms are physiological, not psychological."

Research carried out by Professor Alan Ebringer at King's College London, with whom Sinclair was in close contact while writing her new book, shows that dietary starch may indeed play a key role in IBS. His investigations focused on ankylosing spondylitis (AS), an arthritis involving the spine and large joints, which often gives sufferers IBS symptoms (as was the case for Sinclair). AS patients often have elevated levels of antibodies to a normal bowel bacterium, Klebsiella. Coincidentally, it turns out that the main substance supporting bacterial growth in the colon comes from dietary starch, so controlling the intake of dietary starch reduces the levels of this bacterium in the bowel. A low- starch diet has been used with AS patients in London with great success, often reducing patients' dependence on pain-relieving drugs and restoring a more normal, less crippled existence, particularly in the early stages of the disease. It has also been shown that even non-AS sufferers with "regular" IBS symptoms have antibodies to the Klebsiella bacteria.

In the past I've tried various treatments, such as probiotics – capsules of "friendly" bacteria commonly found in the gut that are supposed to replenish normal levels within your system – eating live yoghurt and taking peppermint tea and capsules. I have even taken laxatives at desperate times of constipation. None of these approaches provided any long-lasting relief, and I've simply learnt, through experience, what food and drink to avoid – red wine is a no-no, as is spicy food, and even onions and cucumber can cause problems.

At around the same time as my sigmoidoscopy, a friend told me that he has also suffered with IBS for years. For him, exercise and drinking lots of water, plus occasional prescription drugs that control colonic spasms, have been his means of controlling his symptoms. Recently I have taken this advice and in addition to drinking at least a litre of water a day, I routinely walk the 25 minutes to the station. I have also started swimming and attend yoga and aerobics classes. My symptoms haven't been this manageable for as long as I can remember, but even now I get occasional bouts of painful bloating that I try to control with prescription antispasmodics.

Even as a relatively mild sufferer of IBS, anything that would offer me an IBS-free life would be very welcome. A microbiologist by degree, I find the theory of a bacterium causing my symptoms feasible. The starch-free diet seems to make sense, and I am encouraged to hear that my IBS may be more than just a "stress-related personality disorder" manifesting with painful, embarrassing symptoms. I plan to try the low-starch diet, and although being vegetarian will make it slightly more difficult to follow, I welcome the prospect of a natural "treatment" that I can control myself, giving me symptom-free days. What a joy it will be to visit even foreign countries without worrying about their toilet facilities!

'The New IBS Low-Starch Diet' is published by Vermilion on 1 May, £9.99