The symptoms of irritable bowel syndrome (IBS) are highly variable, differing greatly from one individual to another and over the course of the disorder. Many symptoms are similar to ones caused by other diseases, and this can make it difficult to correctly diagnose IBS. In general, most people suffering from IBS have pains and cramping in the abdomen, irregularities in bowel movements, gas and bloating. They may have constipation or diarrhea, and stools frequently have excess mucus in them. It is believed IBS does not cause permanent damage to the colon or lead to other diseases.
Patients may experience great differences in the severity of the symptoms of irritable bowel syndrome. Mild abdominal stress and bloating might simply be uncomfortable. At other times, the symptoms can be debilitating, interfering with normal activities. Bowel movements may be frequent and loose causing additional stress, which further aggravates the disorder. At its worst, IBS can interfere with work, relationships and social activities and cause anxiety or depression.
In some patients, recurring periods of severe symptoms alternate with periods of very mild discomfort. Other patients experience escalating symptoms with no intervening periods of relief. The symptoms of irritable bowel syndrome are generally present a minimum of three months out of the year. The abdominal pain is closely associated with or may be relieved by having a bowel movement.
Although the causes of irritable bowel syndrome are unknown, in most patients it seems the colon is not functioning normally. The normal muscular movement in the colon may be too slow or too fast, causing difficulties in bowel movements including constipation or diarrhea. The colon may also be spastic, contributing to bowel irregularities and cramping. It is believed some people have a colon that is oversensitive, reacting unusually to stress and certain foods that aggravate the condition.
Some evidence indicates that irritable bowel syndrome may be caused by bacterial or protozoal infections. Other studies have shown that many IBS sufferers also have anxiety, depression or other psychological problems. Anxiety and stress can make IBS symptoms worse. Patients with IBS are also more likely to have headaches, chronic fatigue syndrome and fibromyalgia.
There are no definitive tests for irritable bowel syndrome, so a physician will use a diagnosis of exclusion when IBS is suspected. Testing for other disorders having similar symptoms will rule out those disorders. The doctor will do a colonoscopy to observe the colon. Blood test, stool samples and imaging tests may also be done. If all tests are negative, the doctor then bases the diagnosis of IBS on the specific symptoms of irritable bowel syndrome and their frequency.