Cause
The exact cause of
(IBS) is not known. But
health experts believe faulty communication between the brain and the
intestinal tract causes the symptoms of IBS.
A complex
combination of elements, including psychological stress, hormones, the
, and chemicals called neurotransmitters,
appears to interfere with messages between the brain and the bowel. The
miscommunication causes abnormal muscle contractions or spasms, which often
cause cramping pain. The spasms may either speed the passage of stool, causing
diarrhea, or slow it down, causing constipation or bloating.
People who have IBS seem to have unusually sensitive intestines. It is
not known why their intestines are more likely to react strongly to the
elements that contribute to IBS. People who have IBS may start having symptoms
because of one or more factors, including:
- Eating (though no particular foods have been associated with
IBS).
- Stress. Stress may affect the movements of the intestines and
also may affect the way a person feels pain. (Stress may also have the same
effect on people who do not have IBS.)
- Trapped gas that causes bloating.
- Hormonal changes, such as during the menstrual cycle.
- Some medicines, such as antibiotics.
- Genetics. IBS may be more likely to occur in people who have a
family history of the disorder.