What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome is a disorder characterized most commonly by abdominal pain, bloating, cramping, constipation, and diarrhea. IBS causes a great deal of discomfor. Most people can control their symptoms with diet, stress management, and prescribed medications.

What are the symptoms of IBS?

Abdominal pain, bloating, and discomfort are the main symptoms of IBS. Symptoms may vary from person to person. Some people have constipation or infrequent bowel movements, and others with IBS experience diarrhea. People with diarrhea frequently feel an urgent and uncontrollable need to have a bowel movement. Other people with IBS alternate between constipation and diarrhea. Also, symptoms may subside or worsen from time to time depending on diet and stress.

IBS Symptoms include:

• Abdominal pain or discomfort.

• A change in frequency of bowel movements

• A change in appearance of bowel movements

• Feelings of uncontrollable urgency to have a bowel movement

• Difficulty or inability to pass stool

• Mucus in the stool

• Bloating

What causes IBS?

• IBS is believed to be due to the abnormal function (dysfunction) of the muscles of the organs of the gastrointestinal tract or the nerves controlling the organs.

• A person’s colon may respond strongly to stimuli such as certain foods or stress that would not bother most people.

• Normal motility, or movement, may not be present in the colon of a person who has IBS. It can be spasmodic or can even stop working temporarily. Spasms are sudden strong muscle contractions that come and go.

• The lining of the colon called the epithelium, which is affected by the immune and nervous systems, regulates the flow of fluids in and out of the colon. In IBS, the epithelium appears to work properly. However, when the contents inside the colon move too quickly, the colon loses its ability to absorb fluids. The result is too much fluid in the stool. In other people, the movement inside the colon is too slow, which causes extra fluid to be absorbed. As a result, a person develops constipation.

How is IBS diagnosed?

IBS is generally diagnosed on the basis of a complete medical history that includes a careful description of symptoms, physical examination, laborabory test, and diagnostic colonoscopy.

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