Irritable Bowel Syndrome



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 and react strongly to food and medicine. Food allergies and certain bacteria may add to the symptoms. IBS may also occur after having the stomach flu.

Risk Factors

IBS is more common in women. It typically begins in young adulthood. Factors that may increase your chances of IBS:

  • Family members with IBS
  • Mental health problems such as stress, anxiety , or depression
  • Abuse (may be associated with IBS)



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 symptoms and past health. A physical exam will be done. In many cases, a diagnosis can be made based on this. Since there is no test for IBS, doctors have created a checklist to make a diagnosis.

Stool and blood tests may be done to rule out other problems. Images of the bowel may also be taken with:

  • X-ray
  • Flexible sigmoidoscopy
  • Colonoscopy
Colonoscopy scope
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There is no cure for IBS. Treatment focuses on controlling symptoms.


The following changes to your diet may help control symptoms:

  • Food diary to track what is eaten and how body responds. Care team can help to assess diary.
  • Gradual changes to diet and tracking changes, if any.
  • Meeting with dietitian to make balanced meal while removing problem foods.

Foods that are more likely to cause problems include:

  • High fat foods, spicy foods
  • Dairy products
  • Onions, cabbage, and other gas-producing food
  • Large amounts of alcohol or caffeine

Foods that may reduce risk of spasm include:

  • Fruits and vegetables
  • Whole grains and other high-fiber foods (more fiber may increase gas and bloating until your body adjusts)

Exercise and Stress Management

Regular exercise can help improve bowel function and other IBS symptoms.

Stress and tension can make symptoms worse. Relaxation techniques may help lower response to stress.

Learning about IBS and talking to others with IBS may also ease stress.


Medicine may help to manage symptoms. Choices may include:

  • Antispasmodic agent
  • Antibiotics
  • High-fiber bulking agent
  • Antiflatulent—gas relief
  • Antidiarrheal agent
  • Low-dose antidepressant
  • Pain reliever
  • Serotonin receptor agonists and antagonists (also called 5-HT3 antagonists)—May be helpful for treating diarrhea, as well as treating other IBS symptoms, like abdominal pain in women.
  • Probiotics —Bacteria that help rebalance the normal bacteria in the colon. There are many probiotics available, but not all have been tested. The most common include Bifidobacterium, Lactobacillus, Escherichia coli, as well as various mixtures.
  • Peppermint oil


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

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.