Irritable bowel syndrome (IBS) is a functional disorder affecting the lower portion of the intestinal tract. IBS does not cause permanent damage to the bowels but rather indicates that the bowel is not functioning normally.It does not cause inflammation or increase the risk of colorectal cancer. The most common symptoms of IBS are abdominal pain, bloating, cramping, gas, diarrhea or constipation, or a combination of both. Other symptoms are visible mucus in the stool, a swollen abdomen, and the feeling of incomplete evacuation with a bowel movement. Women with IBS may experience an increase in symptoms during menstrual periods. (1)
The cause of IBS is unclear. The nerves and muscles in the lower intestinal tract appear to be more sensitive in individuals with IBS than in individuals without this disorder. Various triggers, such as stress, emotional arousal, eating, and gastrointestinal infections can initiate or aggravate the symptoms of IBS.
For individuals with IBS, pain and discomfort, fear of an uncontrollable bowel movement occurring at an inappropriate time, and activation of the stress response aggravate the symptoms but do not cause the symptoms. Both physical stress factors, such as an infection, and psychological stress factors, such as the loss of a job, increase motility in the colon. (2)
To better understand IBS, medical researchers look at the connection between the brain and the gastrointestinal system. The enteric nervous system is responsible for regulating the process of digestion. Communication between the brain and the enteric nervous system is a continuous back and forth process. Researchers believe that a dysfunction in this communication can produce or exaggerate the symptoms of IBS. (2)
Functional disorders of the GI system are often associated with anxiety, depression, and panic and post traumatic stress disorders. Published medical literature indicates that less than half of all individuals with IBS seek treatment for psychiatric disorders. Of those individuals with IBS who do seek treatment, 50 to 90 percent have psychiatric disorders such as generalized anxiety dirsoder and major depression. (3)