by Heather Van Vorous
For many patients, the most common response to a new diagnosis of Irritable Bowel Syndrome is, "What exactly does this mean? What is IBS?"
Once you've seen a gastroenterologist, been through diagnostic tests, and found out your symptoms match the Rome Criteria for IBS, you should finally have a diagnosis you feel is accurate. You've got Irritable Bowel Syndrome. Where do you go from here? One of the most important weapons in your battle against IBS is information. Fortunately, over the past several years a great deal of new information regarding the brain-gut interaction that results in IBS has evolved, and more discoveries are being made all the time.
First of all, it helps to realize that you are not alone. Irritable Bowel Syndrome is estimated to affect 15-20% of all Americans, primarily (but certainly not exclusively) women. This is at least 35 million Americans, and half of them have never even seen a physician for their symptoms. Despite this, IBS is still the most-frequently seen illness by gastroenterologists, and is one the top ten diagnoses among all US physicians. It is also, incredibly, the second leading cause of worker absenteeism (behind only the common cold). These are pretty amazing statistics for a disorder that many people have never even heard of.
Interestingly, because Irritable Bowel Syndrome is a "functional" disorder, you can't actually be tested for it. Rather, it is determined by a diagnosis of exclusion. This is because there are no structural, inflammatory, biochemical, or infectious abnormalities present in IBS. In other words, when IBS patients are examined by doctors, there is no physical problem to be found. Does this mean you're just imagining your symptoms? No - you absolutely are not. A functional disorder simply means that the problem is an altered physiological function (that is, the way your body works), rather than something that has an identifiable origin behind it. In other words, while an IBS attack and its resulting symptoms are clearly visible as physical manifestations, the underlying cause behind these symptoms is not. The root of the problem in IBS sufferers cannot yet be identified by yielding a positive result from any existing medical tests. What then, precisely, is wrong with the way your body works if you have Irritable Bowel Syndrome?
IBS is indisputably a physical problem. Simply put, the brain-gut interaction of people with IBS influences their bowel pain perception and motility. In a nutshell, the processing of pain information within the central nervous system varies between normal individuals and those of us with IBS, with the result that we can experience even normal GI contractions as painful. The interactions between our brains, central nervous systems, and GI systems are just not functioning properly. We have colons that react to stimuli that do not affect normal colons, and our reactions are much more severe. The end result is heightened pain sensitivity and abnormal gut motility, in the form of irregular or increased GI muscle contractions. It is this gut overreaction and altered pain perception that cause the lower abdominal cramping and accompanying diarrhea and/or constipation that characterize Irritable Bowel Syndrome.
Interestingly, the origins of IBS may really be in our brains, and not in our bowels. Given that for many years people with IBS were dismissively told their problem was "all in their heads", it's ironic that, in the end, this may be factually true. The underlying problem might well be in our brains - but it's absolutely not in our imaginations.
No one really yet knows exactly why some people develop IBS and others don't. There is mounting evidence that for some IBS sufferers the condition is precipitated by some type of grievous insult to the gut - dysentery, food poisoning, intestinal flu, abdominal surgery, even pregnancy. The theory goes that even after full physical recovery from these traumatic events, the nerves within the gut retain a "memory" of the insult and remain hyper-sensitive to further stimulation, as well as prone to subsequent over-reaction. You likely know if you experienced any abdominal trauma immediately prior to the onset of your Irritable Bowel Syndrome symptoms, and if you did it's probably nice to have a logical explanation for what has happened to your GI tract and why. There are those (and I'm one of them) who are exceptions to this theory, however, who suffered no gut insult prior to the onset of Irritable Bowel Syndrome symptoms, and we're still patiently waiting for our explanation.
Heather Van Vorous is the author of Eating for IBS and The First Year: Irritable Bowel Syndrome. She is the founder of http://www.helpforibs.com/ - the internet's largest IBS community. Her IBS dietary work has led to clinical research studies of diet and IBS, a nomination for a "Julia Child Cookbook" award, and her inclusion in the 4th edition of Who's Who in Medicine and Healthcare. Her Irritable Bowel Syndrome recipes have been licensed by Novartis pharmaceuticals and her products are recommended by physicians and dietitians across the world. Heather has had IBS since age 9.