Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic * disorder that occurs when the intestines do not function correctly. A person with IBS may experience abdominal pain that often is accompanied by alternating episodes of constipation and diarrhea.

Georgia Goes Solo

Playing the flute was Georgia's favorite activity. When she got to college, Georgia majored in music and performed regularly with the college orchestra. Until her senior year, Georgia always was healthy and able to make it to concerts, but then she began to have problems with her bowel movements. Either she was running to the bathroom constantly because she had diarrhea, or she suffered from constipation. Her symptoms began to interfere with rehearsals and concerts, so she went to the college health center. The doctor diagnosed her with irritable bowel syndrome. The doctor prescribed medication for Georgia and referred her to a nutritionist and a stress-management program. By graduation, Georgia was able to play a flute solo without having to worry about rushing off to the bathroom.

What Is Irritable Bowel Syndrome?

Irritable bowel syndrome is a disorder in which the nerves that control the muscles of the intestine are unusually sensitive, causing the bowels to function improperly. The result is abdominal discomfort and an altered pattern of bowel movements (either diarrhea * or constipation * ). Studies estimate that IBS affects 10 to 15 percent of U.S. adults, but only 5 to 7 percent of U.S. adults have received a diagnosis of IBS.

IBS, which is also called spastic colon or spastic bowel, is not contagious; a person cannot catch it from someone who has it. IBS does not lead to other intestinal diseases such as cancer * or ulcerative colitis * . IBS may be only a minor inconvenience for those with mild symptoms, but for those with more severe symptoms it can have a significant impact on their emotional wellbeing and professional and social life.

The cause of IBS is unknown. Diet, drugs, stress, hormones, or emotional factors such as anxiety or depression can trigger symptoms, and these triggers vary from person to person. The syndrome is about twice as common in women as in men and usually begins in early adulthood.


Irritable bowel syndrome is sometimes confused with inflammatory bowel disease (IBD), but they are not the same thing. IBD is a term used for conditions that are characterized by chronic or recurring inflammation of the intestines. This inflammation does not occur in IBS. IBD happens when the body's immune system mistakes food and bacteria in the gastrointestinal tract for foreign objects and sends white blood cells to the area, which causes inflammation. The two most common IBD disorders are Crohn's disease and ulcerative colitis.

Many of the symptoms of Crohn's disease and ulcerative colitis are similar. Both can produce diarrhea, abdominal pain, and bloody stool. Crohn's, however, can occur in any part of the gastrointestinal tract while ulcerative colitis only occurs in the large intestine. In Crohn's, there are healthy parts of the colon in between the inflamed areas, but this is not the case in ulcerative colitis. And in ulcerative colitis, only the innermost lining of the colon is affected.

IBD is a more serious condition than IBS and is generally more disruptive to a person's lifestyle. Complications of IBD can include malnutrition, scarring of the bowels, and fistulas, which occur when a sore extends completely through the intestinal wall and causes two parts of the body to connect that should not, such as the bowel and the bladder. With IBS, there is no permanent damage done to the intestines.

Those with a family history of the disorder are more likely to suffer from IBS, suggesting genetics may play a factor.

What Are the Symptoms of Irritable Bowel Syndrome?

To be diagnosed with IBS, a person must experience symptoms for at least three days a month for a period of at least three months. Abdominal discomfort is the main symptom of IBS. This discomfort may come in the form of cramps, or the person may experience a more steady aching sensation with cramps that come and go. Other symptoms can include the following:

Some people may have symptoms that do not involve the stomach, such as fatigue, sleep disturbances, and headaches. Blood in the stool and unexplained weight loss are not symptoms of IBS and may be signs of a more serious illness.

How Is IBS Diagnosed and Treated?


There are certain criteria, called the Rome criteria, that doctors typically use to diagnose IBS. The patient must have pain and discomfort that has continued or recurred for at least three months and that is (1) relieved by having a bowel movement, (2) accompanied by an increase or decrease in frequency of bowel movements, and/or (3) associated with stool becoming harder or softer in consistency.

Foods to Avoid to Ease IBS Symptoms

A patient must meet two of these three criteria before the doctor will diagnose IBS. A second set of criteria, the Manning criteria, focuses on other symptoms, such as pain relief after a bowel movement, mucus in the stool, and incomplete bowel movements. The more of these symptoms a person has, the more likely he or she has IBS.

Symptoms not associated with IBS, such as anemia * , unexplained weight loss, or bloody stools, may make further examination necessary. The doctor may test blood and stool samples or take x-rays or perform a colonoscopy * to rule out other disorders, such as Crohn's disease or ulcerative colitis.

In 2015 researchers were working on a blood test that could detect IBS. In a clinical trial involving approximately 2,700 subjects, the test was found to be highly accurate at distinguishing irritable bowel syndrome from Crohn's or ulcerative colitis.


While there is no cure for IBS, various methods can be effective in controlling the symptoms. Doctors may prescribe medication to control diarrhea and constipation, and certain medications can help relieve the abdominal pain. Changes in diet help many people control their symptoms. People with IBS often benefit from practicing stress-reduction techniques, because stress can lead to symptoms in some people. A study in late 2015 found that several types of psychological therapies, such as relaxation therapy and hypnosis, led to a moderate lessening of IBS symptoms in 75 percent of the treatment group.

See also Constipation • Diarrhea • Gastroenteritis • Inflammatory Bowel Disease


Books and Articles

Zinser, Stephanie. The Good Gut Guide: Help for IBS, Ulcerative Colitis, Crohn's Disease, Diverticulitis, Food Allergies and Other Gut Problems. London: Thorsons, 2012.


National Institute of Diabetes and Digestive and Kidney Diseases. “Definition and Facts for Irritable Bowel Syndrome.” (accessed April 7, 2016).

National Institute of Diabetes and Digestive and Kidney Diseases. “Irritable Bowel Syndrome in Children.” (accessed April 7, 2016).


American Gastroenterological Association. 4930 Del Ray Ave., Bethesda, MD 20814. Telephone: 301-654-2055. Website: (accessed April 7, 2016).

International Foundation for Functional Gastrointestinal Disorders. 700 W. Virginia St., Suite 201, Milwaukee, WI 53204. Toll-free: 888-964-2001. Website: (accessed April 7, 2016).

National Institute of Diabetes and Digestive and Kidney Diseases. 9000 Rockville Pk., Bethesda, MD 20892. Telephone: 301-496-3583. Website: (accessed April 7, 2016).

* chronic (KRAH-nik) means lasting a long time or recurring frequently.

* diarrhea (di-ah-RE-a) refers to frequent, watery stools (bowel movements).

* constipation is the sluggish movement of the bowels, usually resulting in infrequent, hard stools.

* cancer is a condition characterized by abnormal overgrowth of certain cells, which may be fatal.

* ulcerative colitis (ko-LIE-tis, ULsir-ah-tivs) is a common form of inflammatory bowel disease that causes inflammation with sore spots or breaks in the inner lining of the large intestine (colon). Symptoms include cramping, bleeding from the rectum, and diarrhea.

* colonoscopy is a medical procedure in which an instrument is inserted into the colon in order to take pictures of it.

* anemia is a condition in which a person has fewer red blood cells than normal. This results in weakness and tiredness.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)