Description of Irritable Bowel Syndrome

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Irritable bowel syndrome is a condition in which patients experience changes in bowel movements, as well as abdominal cramping and pain. Through a description of irritable bowel syndrome, we know that this condition does not cause changes in bowel tissue or inflammation. It also does not increase the risk of developing colorectal cancer. Only few patients have signs and symptoms that are severe. It is estimated that in the United States, about one in five adults experience the signs and symptoms of this condition.

Causes and Risk Factors

The exact cause is uncertain, but it is known that the intestinal muscle contractions tend to last longer and be stronger than they normally are. This forces the food through the intestines faster, resulting in symptoms such as bloating, gas and diarrhea. The opposite may occur in some cases.

Colon or nervous system abnormalities may also be responsible for this condition, causing more discomfort than is normal when the patient experiences gas-related abdominal stretching. There are certain triggers as well, but not all patients have the same triggers. These triggers include foods, hormones, stress and other medical conditions, such as acute infectious diarrhea.

Risk factors may include being female, being 35 or older, and a family history of this condition.

Signs, Symptoms, and Complications

Signs and symptoms differ greatly among patients and may include:

  • Abdominal cramping or pain
  • Gas
  • Mucus in the stool
  • Feeling bloated
  • Constipation or diarrhea

Symptoms can range greatly from mild to severe. The description of irritable bowel syndrome categorizes it as a chronic condition, though patients may have episodes in which their symptoms are more prominent.

This condition may result in hemorrhoids due to constipation and diarrhea. Also, if a patient cannot have certain foods, he or she may experience malnourishment. This condition may also hinder the patient’s sex life, ability to make plans and attend social events or even promotions in the workplace due to excessive sick days.


A physical exam and the patients medical history plays a large role in diagnosing this condition. This condition is often diagnosed through process of elimination. Certain criteria are used to make a diagnosis. Most importantly, the patient should have been experiencing abdominal discomfort and pain for a minimum of 12 weeks, but these weeks do not necessarily have to be back to back. At least two of the following should also be present:

  • Urgency, straining, or feeling as if the bowels cannot be completely emptied
  • Abdominal distention or bloating
  • Change in consistency or frequency of the patient’s stool
  • Mucus in the stool

Additional testing may be necessary, such as:

  • Colonoscopy
  • Lactose intolerance tests
  • Flexible sigmoidoscopy
  • Computerized tomography scan
  • Blood tests


This condition cannot be cured, but for most patients, the signs and symptoms can be controlled. Commonly used treatment methods include:

  • Fiber supplements
  • Not consuming high-gas foods
  • Antidepressant medications
  • Anti-diarrheal medications
  • Anticholinergic medications
  • Antibiotics
  • Counseling

Medications specifically used to treat this condition include alosetron and lubiprostone.

Prognosis is typically good for patients. As long as their signs and symptoms are well-controlled, most patients can live a normal life.


Mayo Clinic. (2009). Irritable Bowel Syndrome. Retrieved on January 5, 2011 from Mayo Clinic:

MedlinePlus. (2010). Irritable Bowel Syndrome. Retrieved on January 5, 2011 from MedlinePlus: