What causes IBS?

There is no known cause of IBS.  Many experts believe that the colon overreacts to different stimuli such as stress or emotions while others believe it is related to food sensitivities.

Too much fat in the diet could aggravate IBS.  Lactose intolerance, eating too fast or not eating at regular intervals and smoking, they could all have an impact in IBS.  Aspartame and sugar substitutes can stimulate diarrhea.

Prevention

Having enough fiber in your diet is a must, whether you are having constipation or diarrhea.  The recommended daily intake of fiber is 30 grams, however most adults ingest less than 20 grams of fiber a day.  Avoid too much caffeine in your diet.  Quit smoking.
To cope with stress there are lots of options.  Meditation, yoga, visualization, guided imagery, exercise and walking.

How do you know if you have IBS?

There is no specific medical test that diagnoses IBS.  The most common test that your doctor will perform is a stool test from which more serious conditions can be ruled out.   You may find out that you have parasites, in which case the removal of such parasites will eradicate your digestive problems.

A blood test may also be performed as it will indicate if you are suffering from anemia or another condition that is causing same symptoms as IBS.

Examinations of the rectum and large intestine through  colonoscopy or sigmoidoscopy are other tests that your doctor may want to perform to diagnose IBS.

Other tests may include the barium enemas which consists of a series of x-rays of the lower intestine after the enema.  Barium is a whitish metallic compound that helps to outline and see the image of the intestines on the x-rays.

Your doctor may also ask questions about your personal history, including factors that may be causing you emotional stress or psychological difficulties.
Since IBS does not have a particular underlying cause, treatments are aimed at relieving the symptoms.