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IBS is a functional disorder of the gastrointestinal (GI) system. In IBS, there is no damage or visible sign of disease in the large intestine, but it does not work properly. IBS can cause diarrhea, constipation, or a mixture of both, along with abdominal pain, bloating, heartburn, and other symptoms. IBS can significantly impact quality of life, negatively affecting work, relationships, social life, and travel.
What is IBS?
The cause of irritable bowel syndrome is unknown, although researchers have identified many risk factors associated with developing IBS. Some doctors consider functional GI disorders to be caused by communication problems between the gut and the brain.
There are three types of irritable bowel syndrome. IBS-C mainly involves constipation; IBS-D involves mainly diarrhea; and IBS-M involves constipation on some days and diarrhea on other days.
The history of IBS
The first medical case describing irritable bowel syndrome was recorded in 1820 in the United Kingdom. Early case studies noted bloating, abdominal pain, and irregular stools. The term "irritable bowel syndrome" was first used in 1944. Other terms used to refer to IBS over time have included irritable colon, spastic colon, nervous colon, colitis, mucous colitis, and spastic bowel.
In 1978, physician A.P. Manning of Duke University established the Manning criteria for IBS diagnosis. The Manning criteria are based on abdominal pain and loose stools. The Rome III criteria, written in 2006, describes types of IBS according to bowel habit. Both sets of criteria are still used today.
How common is IBS?
An estimated 12 to 15 percent of the United States population has IBS. IBS is one of the most commonly diagnosed gastrointestinal conditions in the U.S. Women are about twice as likely to develop IBS as men. Most people who develop IBS are under the age of 50.
Can you die from IBS?
Irritable bowel syndrome has no effect on life expectancy. People with IBS can expect to live a normal lifespan. IBS is not progressive and does not cause damage to the gastrointestinal system.
How is IBS diagnosed?
Doctors diagnose irritable bowel syndrome with a combination of detailed patient history and tests to screen for other potential causes of your symptoms. Tests may include endoscopy, X-ray or computed tomography (CT) scan, breath tests, and collection of a stool sample. It can take time to receive a definitive diagnosis, and many people receive incorrect diagnoses before finding out they have IBS. Learn more about the IBS diagnosis process.
What are the symptoms of IBS?
How is IBS treated?
People with IBS are encouraged to identify and avoid foods that trigger symptoms and make life changes such as getting plenty of sleep and exercise. Laxatives, anti-diarrhea drugs, and fiber supplements may help, and prescription medications can help regulate the digestive tract and keep it moving in a more normal fashion. Some people with IBS benefit from antidepressants. Learn more about IBS treatments.
Are IBD and IBS one and the same?
Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are two separate and unrelated conditions that share many of the same symptoms including constipation, diarrhea, urgent need to defecate, abdominal pain, and cramping. However, IBS does not involve inflammation or damage to the digestive tract. IBD causes damage that can be seen on imaging tests and inflammation that can be measured with blood tests. IBS does not cause bleeding, which is common in IBD, or complications such as abscesses or fistulas. In IBS, symptoms are caused by functional problems of the digestive system, specifically, the pattern in which the muscles that line the GI tract move food along.
The cause of IBS is unknown, but it is not believed to involve an abnormal reaction of the immune system as in IBD. A few medications may be effective at treating symptoms (such as such as constipation and diarrhea) of both IBD and IBS; however, IBD itself is treated with immunomodulators and surgeries that would be ineffective and dangerous in cases of IBS.
Is it possible to have both IBD and IBS?
Yes, it is rare but possible to have both inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). Approximately 20 percent of people diagnosed with either Crohn’s disease or ulcerative colitis experience symptoms of IBS at the same time.