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Irritable Bowel Syndrome

Irritable Bowel Syndrome Symptoms and Causes

Irritable Bowel Syndrome (IBS) Description

Irritable bowel syndrome is a problem that affects the large intestine. Although IBS can cause a great deal of discomfort, it does not harm the intestines. The digestion and propulsion of nutrients and fluids through the gastrointestinal system (GI) is a very complicated and very well organized process. The GI tract has its own intrinsic muscles and nerves that connect, like an electrical circuit, to the spinal cord and brain. As a result of this activity, motility (spontaneous movement) and sensation in the bowel is generated. An abnormality in this process results in a disordered propulsion of the intestinal contents, which generates the sensation of pain.

Irritable bowel syndrome has inaccurately been called by many names, including the following:

  • Colitis
  • Mucous colitis
  • Spastic colon
  • Spastic bowel
  • Functional bowel disease

Irritable Bowel Syndrome Symptoms

The most common symptoms of Irritable Bowel Syndrome may include:

  • Crampy abdominal pain
  • Painful constipation and/or diarrhea.
  • Alternating constipation and diarrhea
  • Mucus in the bowel movement

Bleeding, fever, weight loss, and persistent, severe pain are not symptoms of IBS, but indicate other problems.

Irritable bowel syndrome often causes a great deal of discomfort and distress, but it is not believed to cause permanent harm to the intestines, lead to intestinal bleeding of the bowel, or lead to a serious disease such as cancer. Irritable bowel syndrome has not been shown to lead to serious, organic diseases, nor has a link been established between IBS and inflammatory bowel diseases such as Crohn's disease or ulcerative colitis.

Irritable Bowel Syndrome Causes

IBS is called a functional disorder because there is no sign of disease when the colon is examined. Because physicians have been unable to find an organic cause, IBS often has been thought to be caused by emotional conflict or stress. While stress may worsen irritable bowel syndrome symptoms, research suggests that other factors also are important irritable bowel syndrome causes.

One theory is that a person with IBS may have a colon that is more sensitive and reactive than usual, so it responds strongly to stimuli that would not affect others. The colon muscle of a person with IBS then begins to spasm after only mild stimulation or ordinary events such as the following:

  • Eating
  • Distention from gas or other material in the colon
  • Certain medications
  • Certain foods

Women with IBS seem to have more symptoms during their menstrual periods, suggesting that reproductive hormones can increase irritable bowel syndrome symptoms.