What is Irritable Bowel Syndrome (IBS)?
by Olafur S. Palsson, Psy.D.
Information on this page was last updated March 27, 2008
IBS is one of the most common functional disorders of the gastrointestinal (GI) tract. Like other functional GI disorders, IBS consists of abnormal changes in the way the gut normally functions, without any detectable structural changes. IBS is characterized by recurrent abdominal pain and discomfort, accompanied by changes in bowel functioning such as diarrhea, constipation or a combination of both. These symptoms typically last for years after they come on, but are often intermittent. It has been estimated that 10-15% of adults in the United States suffer from IBS, and a similar prevalence is seen in many other countries. The disorder is the most commonly seen problem in practice by gastroenterologists, and is sometimes found to be among the top ten presenting problems in primary care settings. IBS exhibits a predominance in women, with females representing over 70% of IBS sufferers.
Rome III criteria for IBS: Abdominal pain or abdominal discomfort at least 3 days a month in the last 3 months, where at least 2 of the following were also true: The pain/discomfort was relieved by defecation and/or the start of the pain/discomfort was associated with altered stool frequency and/or the start of the pain/discomfort was associated with altered stool form (appearance).
However, in addition to ensuring that the symptoms meet the criteria for IBS, it is often important to do some testing to exclude other disorders which may produce similar symptoms as IBS. Such testing may include a blood sample to rule out infection, sigmoidoscopy or colonoscopy to look for lesions or other abnormalities in the intestines, and a stool sample to rule out parasite infection or bleeding in the gut. Some of the possible problems which may be misdiagnosed as IBS are Crohn's disease, ulceritive colitis, and lactose intolerance. For this reason, it is important to have a physician thoroughly assess the problem.