Irritable Bowel Syndrome
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Irritable Bowel Syndrome

(Functional Colitis; IBS; Intestinal Neurosis; Irritable Colon; Laxative Colitis; Mucous Colitis; Nervous Indigestion; Spastic Colon)

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Irritable bowel syndrome (IBS) is a chronic disorder of the intestines. IBS does not cause inflammation and does not lead to a more serious condition.


The cause is unknown. With IBS, the muscles in the colon do not work normally and may spasm. If you have IBS, your colon may be more sensitive, reacting strongly to food and medication. Food allergies and certain bacteria may add to the symptoms. IBS may also occur after having the stomach flu (called gastroenteritis ).

Risk Factors

These factors increase your chance of developing IBS:

  • Sex: female
  • Family members with IBS
  • Age: typically begins in young adulthood
  • Stress
  • Abuse (may be associated with IBS)

Tell your doctor if you have any of these risk factors.


Symptoms usually come and go and range from mild to severe. They include:

  • Abdominal cramps
  • Gas and bloating
  • Pain that resolves with a bowel movement
  • Loose stools
  • Diarrhea
  • Constipation
  • Alternating diarrhea and constipation
  • Urge to move bowels again immediately following a bowel movement
  • Mucus in the stool

These factors may worsen your symptoms:

  • Stress
  • Menstrual periods
  • Large meals or fatty foods
  • Excess gas


The doctor will ask about your symptoms and medical history, and perform a physical exam. In many cases, a diagnosis can be made based on this. Since there is no diagnostic test for IBS, doctors have created criteria for making a diagnosis.

Your doctor may order the following tests to rule out other conditions:

  • Analysis of a stool sample to check for blood or evidence of inflammation
  • Blood tests
  • Barium enema —injection of fluid into the rectum to make the colon show up on an an x-ray , allows the doctor to see abnormal spots in the colon
  • Flexible sigmoidoscopy —a thin, lighted tube inserted into the rectum to examine the rectum and the lower colon
  • Colonoscopy —a thin, lighted tube inserted through the rectum and into the colon to examine the lining of the entire colon


Colonoscopy scope

© 2008 Nucleus Medical Art, Inc.


There is no cure for IBS. Treatment focuses on controlling symptoms.


The following changes to your diet may help control symptoms:

  • Keep a food diary of what you eat and how your body responds. Share this with your doctor. You may have a food allergy.
  • Make gradual changes to your diet. Record the results.
  • Avoid foods that have caused problems in the past. A dietitian can help you substitute foods.
  • Avoid foods and drinks that may cause symptoms:
    • High fat foods, spicy foods
    • Dairy products
    • Onions, cabbage, and other gas-producing food
    • Large amounts of alcohol or caffeine
  • Eat foods that may reduce the chance of spasm, such as:
  • Eat smaller meals more often or smaller portions.
  • Eat slowly and try not to swallow air.
  • Drink plenty of water. This will help to reduce constipation.

Stress Management

Talk to your doctor about ways to reduce stress , such as:


Depending on your symptoms, your doctor may prescribe:

  • Antibiotic (eg, Rifaximin may help symptoms for several months.)
  • Antispasmodic agent (eg, dicyclomine )
  • High-fiber bulking agent (eg, psyllium )
  • Antidiarrheal agent (eg, loperamide )
  • Low-dose antidepressant
  • Pain reliever (eg, acetaminophen )—A study showed modest benefit of acetaminophen for treatment of crampy abdominal pain in patients with IBS. * 1
  • Serotonin receptor agonists and antagonists—may be helpful for women (eg, tegaserod for constipation, alosetron for diarrhea)
    • Note: Tegaserod was withdrawn from the market in March 2007. This was due to a slightly increased risk of heart attack , angina , and stroke . * 2
  • Probiotics ("friendly" bacteria)—may be helpful, but talk to your doctor before taking


There are no guidelines for preventing IBS because the cause is unknown.


American College of Gastroenterology

American Gastroenterological Association

Irritable Bowel Syndrome Association


Health Canada

Irritable Bowel Syndrome Association


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Talley NJ, Boyce PM, Jones M. Is the association between irritable bowel syndrome and abuse explained by neuroticism? A population based study. Gut. 1998;42: 47-53.

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* 1 9/26/06 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Mueller-Lissner S, Tytgat GN, Paulo LG, et al. Placebo-and paracetamol-controlled study on the efficacy and tolerability of hyoscine butylbromide in the treatment of patients with recurrent crampy abdominal pain. Alimentary Pharmacology and Therapeutics . 2006;23:1741-1748.

* 2 4/10/07 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : US Food and Drug Administration. FDA announces discontinued marketing of GI drug, Zelnorm, for safety reasons [press release]. March 30, 2007. US Food and Drug Administration website. Available at:

Last reviewed November 2007 by Daus Mahnke, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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