Irritable bowel syndrome (IBS) or spastic colon is a functional bowel disorder characterized by abdominal pain and changes in bowel habits which are not associated with any abnormalities seen on routine clinical testing .This refers to a "disorder of functioning" where the body's normal activities in terms of the movement of the intestines, the sensitivity of the nerves of the intestines, or the way in which the brain controls some of these functions is impaired. It is fairly common and makes up 20-50% of visits to gastroenterologists (doctors who specialize in medical treatment of disorders of the stomach and intestines) and affects approximately 10-20% of the general population.


IBS symptoms vary from person to person, and can be anything from a mild inconvenience to an agonising experience. Typical IBS symptoms include:

  • diarrhea
  • constipation
  • alternating diarrhea and constipation
  • bloating
  • excess gas or wind
  • abdominal pain
  • nausea


The precise cause of irritable bowel syndrome is unknown. The condition often begins during a period of emotional stress and symptoms worsen in stressful situations.

Up to 60 per cent of people with the syndrome have psychological symptoms such as anxiety and depression. The disorder sometimes develops after a gastrointestinal infection. An increased sensitivity or intolerance to certain foods may also contribute.

It may result from exaggerated contractions of the muscles in the intestinal walls. These abnormal contractions can be tested by placing pressure-sensing devices in the colon. The colon muscle of a person with IBS begins to spasm after only mild stimulation and is more sensitive and reactive than usual.

The chemical transmitter that mediates the change to pressures within the bowel has been identified as serotonin, a chemical found in the brain as well as in the bowel. Ninety-five per cent of serotonin is found in the bowel where it is mainly concerned with the contraction of the smooth muscle in the bowel wall. The exact mechanism is not known but serotonin receptors are thought not to function properly in IBS patients.


Commonly Prescribed Treatment

Although there is no cure for irritable bowel syndrome, there are things people can do to alleviate the symptoms. The most commonly prescribed treatment is eating a high fiber diet and taking bulk forming agents. Antispasmodic drugs to relieve muscle spasms , antidiarrheal drugs to relieve prolonged diarrhea or laxatives to relieve severe constipation may also be prescribed. Additionally, careful selection of foods is recommended. If a food repeatedly causes symptoms, it's advisable to eliminate it from the diet.

Lifestyle Changes

Smaller portions at mealtimes may help to prevent bloating and cramping. Instead of three large meals every day, five smaller meals may also help in reducing symptoms. Eating a healthy diet, drinking plenty of water, and getting daily exercise are also helpful in reducing IBS symptoms. These changes can also contribute to an overall healthy lifestyle.

Stress Reduction

Relaxation training, in addition to medical therapy, can also help to reduce symptoms.