Irritable bowel syndrome (IBS) is a disorder of bowel function (as opposed to being due to an anatomic abnormality). Patients who suffer from irritable bowel syndrome have changes in bowel habits such as constipation or diarrhea, and abdominal pain along with other symptoms including abdominal bloating, and rectal urgency with diarrhea. In addition, irritable bowel syndrome may be associated with a number of non-intestinal ("extraintestinal symptoms"), such as difficulty with sexual function (pain on intercourse or lack of libido), muscle aches and pains, fatigue, fibromyalgia syndrome, headaches, back pain, and sometimes urinary symptoms including urinary urgency, urinary hesitation or a feeling of spasm in the bladder.
IBS is an extremely common disorder. Studies have estimated the prevalence in the United States is somewhere between 10% and 15% of the entire population. IBS is seen in similar frequencies in other countries around the world. Most studies suggest that irritable bowel syndrome is more common in women with almost twice as many women having the disorder compared to men. The reason why women are more commonly affected by irritable bowel syndrome is not completely understood. It does not seem to be merely due to hormonal differences between men and women. Rather it seems to be due to differences in how women and men process sensations from the intestines, both in the intestinal nervous system ( "enteric nervous sytem") as well as the brain and spinal cord ("central nervous system"). The frequency of IBS seems to be the same across racial, ethnic and national boundaries.
Despite the fact that irritable bowel syndrome is so common, most people with IBS do not see a doctor for their symptoms. It is estimated that only 1 in 4 people with IBS see a doctor (and thus become a patient with IBS). Reasons why some people chose to see a doctor and others do not are not completely understood. Interestingly the severity of gastrointestinal symptoms from IBS alone does not seem to be the major driving factor. Rather the impact of IBS on the patient's ability to function on a day-to-day basis while having IBS symptoms, the stress from having IBS, and concerns about other diseases that they might have are some of the more frequent reasons patients see their doctor for IBS like symptoms.
Irritable bowel syndrome is not associated with serious medical consequences. People with IBS tend to live long, and in some studies, somewhat longer than individuals who do not have IBS. IBS is not a risk factor for other serious GI diseases, such as inflammatory bowel disease (Crohn's disease or ulcerative colitis) or colon cancer. The presence of IBS does not put extra stress on the other organs in the body such as the heart, liver or kidneys. Overall the prognosis for irritable bowel syndrome is excellent. Patients suffering from IBS should not be worried about it leading to other serious diseases. The major problem with IBS is not that it causes death, but because it changes the quality of life for people who suffer from it. In the last 20 years, we have come to understand how important quality of life is for patients suffering from health problems (called 'health related quality of life', HRQOL for short). We now understand that the severity of all diseases, not just IBS, cannot be measured only with tests or how severe symptoms are. Rather we have begun to understand that the true measure of the impact of any disorder is the negative impact on a patient's HRQOL. In IBS, health related quality of life is usually not as good compared to people who do not have IBS. This makes IBS a particularly troublesome disorder.
Studies have shown that that when compared to patients with diabetes, gastro esophageal reflux disease (GERD), as well as individuals who have no gastro intestinal disorders, patients with IBS had significantly higher degrees of impairment in their quality of life. By this is meant their physical functioning, their ability to participate in the activities of daily living, their level of emotional distress, as well as their sexual functioning and all the other components that go into a happy and healthy normal life without disease. This is the true impact of IBS and is an important reason that it deserves serious attention from the medical community. IBS is also a costly disease, not only in terms of money spent for health care but also money lost because of a patient's inability to work while they have symptoms. It is estimated that IBS causes a loss of $30 to $90 billion per year in productivity. After the common cold, IBS is the second most frequent reason people take days off from work in the United States. This makes IBS a very important issue for the society in general, which clearly needs to be addressed by the medical community.
Irritable bowel syndrome is not a trivial illness. It deeply affects the quality of life of the patient and their ability to function effectively in society. The economic cost of irritable bowel syndrome has been estimated to be over $80 billion a year to the American economy. However, above and beyond this is the large number of people in our society who experience IBS symptoms daily who in the past have suffered in silence because there were no effective treatments available. Patients with IBS should see their physician and get recommendations on the latest treatments available. However, it is also important that the patient with IBS understand that although this is a chronic illness, symptoms can be controlled, and the overall prognosis is actually quite good.