What is irritable bowel syndrome?
4/13/2023 by Stacey Rolak, M.D., M.P.H.
Irritable bowel syndrome, or IBS, is a chronic gastrointestinal (GI) disease that affects your small and large intestine.
What causes IBS?
The exact cause of IBS is not known. It is likely a mix of problems with muscle contractions in the gut, higher pain response to gas or stool in your digestive system, and changes in the gut microbiome. Certain foods, drinks and stress can make your symptoms worse. It also can be triggered after diarrhea caused by bacteria or a virus.
What are the symptoms?
Recurrent abdominal pain that is usually one or more times per week, with two or more of the following:
- Change in the frequency of bowel movements.
- Change in bowel movement appearance.
- Change in abdominal pain, either improvement or worsening, after a bowel movement.
You also may feel bloated. You may have primarily diarrhea, primarily constipation or a mix of the two, which can change over time.
Who gets IBS?
IBS is common and affects 1 in 20 people. It is more common in people younger than 50 and people with a family history of IBS. While more common in women, men can have IBS as well. Those with anxiety, depression or other mental health issues are at higher risk.
How is IBS diagnosed?
If your primary symptom is diarrhea, you may be tested for celiac disease and have stool and blood tests to look for inflammation. If your primary symptom is constipation that is hard to treat, you may need to be tested for pelvic floor dysfunction. You do not routinely need food allergy testing, stool testing for infection or a colonoscopy. It is important that your colon cancer screening be up to date.
How is IBS treated?
While there is no cure for IBS, symptoms can be controlled with:
- Diet: Avoiding or eliminating foods that trigger symptoms. Eat foods high in soluble fibers (e.g., oat bran, beans, barley).
- Over-the-counter medications (OTC) may be helpful to manage constipation — including stool softeners, bulk-forming laxatives or with the addition of stimulant laxatives. Loperamide may be used for managing diarrhea .
- If OTC medications don't work, your primary care clinician may prescribe other medications for constipation (e.g., lubiprostone, linaclotide) or diarrhea (e.g., eluxadoline, rifaximin) which can help symptoms.
- Other options: Peppermint oil, probiotics, exercise, stress reduction and gut-directed psychotherapy have been found to help some people.
Are people with IBS at higher risk for cancer?
No, having IBS does not place you at higher risk of colon cancer than the rest of the general population.
Inform your primary care clinician if you experience fevers, unexplained weight loss, blood in the stool, iron deficiency, diarrhea at night, or significant abdominal pain or nausea with vomiting. This may indicate a more serious condition.
Stacey Rolak, M.D., M.P.H.., is a resident physician in internal medicine at Mayo Clinic in Rochester, Minnesota. She earned her medical degree at the University of Wisconsin School of Medicine and Public Health and her Master of Public Health from George Washington University. She is interested in patient education and preventive care.