IBS (Irritable Bowel Syndrome) Triggers and Prevention

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: Bhupinder S. Anand, MBBS, MD, DPHIL (OXON)
    Bhupinder S. Anand, MBBS, MD, DPHIL (OXON)

    Bhupinder S. Anand, MBBS, MD, DPHIL (OXON)

    Dr. Anand received MBBS degree from Medical College Amritsar, University of Punjab. He completed his Internal Medicine residency at the Postgraduate Institute of medical Education and Research, Chandigarh, India. He was trained in the field of Gastroenterology and obtained the DPhil degree. Dr. Anand is board-certified in Internal Medicine and Gastroenterology.

  • Medical Reviewer: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Quick GuideIBS - Irritable Bowel Syndrome: Symptoms, Diet, Treatment

IBS - Irritable Bowel Syndrome: Symptoms, Diet, Treatment

What foods in the diet trigger constipation in IBS?

Any food or fluids that tend to dehydrate a person is likely to trigger constipation in people with irritable bowel syndrome. Foods that may promote constipation and should be avoided in an IBS diet include:

  • Chocolate
  • Dairy products such as milk and cheese (particularly those that contain lactose)
  • Red meat
  • Unripe bananas
  • Items that contain caffeine if you are slightly dehydrated.
  • Coffee, carbonated drinks and alcohol may lead to dehydration and constipation in IBS patients (and other people, too).

Foods that help prevent constipation in IBS

Foods that help prevent constipation and should be included in an IBS diet include:

  • Prunes
  • Various types of beans
  • Whole grain breads like rye bread
  • Pears and fruits like kiwi
  • Vegetables that will help boost fiber intake

What foods in the diet trigger diarrhea in IBS?

  • Several foods may play a role in developing diarrhea in people with IBS. Major categories of foods that are thought to contribute are those that contain fats (fatty meats, fatty dairy products, for example). Each individual is slightly different and may respond differently to food types. Consequently dietitians and health care professionals who treat people with IBS often suggest that they keep a journal or diary to track those foods that cause diarrhea.
  • Some foods that trigger diarrhea do so because they are ingested in large quantities; for example, a bite of a banana may not cause diarrhea, but eating a whole banana in some people with IBS may trigger diarrhea.
  • Other foods that contain high levels of fructose, artificial sweeteners, high FODMAP foods, and fried foods may also trigger diarrhea.
  • Broccoli, onions, cabbage and large helpings of beans may produce gas and increase the discomfort of diarrhea.
  • Probiotics may help reduce the symptoms of diarrhea and gas in some individuals.

What prescription or OTC drugs trigger IBS?

Some drugs can trigger IBS symptoms resulting in colonic spasms, constipation and/or diarrhea. Such drugs include antibiotics (especially those administered over a long period of time), tricyclic antidepressants, for example, amitriptyline (Elavil, Endep) nortriptyline (Pamelor), and doxepin, and medicines containing sorbitol (for example, some cough syrup preparations and common pain medicines like Advil gel capsules). Consequently, patients with the condition should check the ingredients, both active and inactive, for the presence of sorbitol as sorbitol is often listed as an "inactive" ingredient.

What are the other IBS triggers?

Other triggers of IBS are variable and differ from person to person. However some other common triggers include:

  • Lack of exercise
  • Eating foods too quickly
  • Eating while under some other stress such as driving or working
  • Eating foods that are very hot or cold
  • Chewing gum

Keep a journal and record the symptoms and the activities you are doing when symptoms develop. This can help you determine your personal triggers for any symptoms. Researchers also suggest that changes in hormone levels and/or other acute illnesses such as infectious diarrhea may also trigger symptoms.

Which specialties of doctors treat irritable bowel syndrome?

Although a patient's primary care physician may care for IBS patients, specialists in gastroenterology, immunology, psychiatry and dietary professionals may be consulted to help patients manage the condition.

How can I prevent IBS triggers?

There are many different ways to help prevent you from triggering IBS symptoms such as:

  • Eat a balanced diet with a moderate amount of fiber.
  • Avoid extremes of food temperatures (very hot or cold foods).
  • Do not eat while experiencing anxiety or under stressful conditions (for example, while working or driving).
  • Avoid foods and drinks that may cause dehydration or diarrhea.
  • Keep a journal to help identify those foods that are do or do not trigger symptoms.
  • Try biofeedback, exercise, meditation, or yoga to reduce anxiety.
  • Discuss medications you are taking that may be triggering symptoms with your doctor.
  • Avoid those foods and drinks that are likely to increase or trigger symptoms.
  • Avoid foods that increase intestinal gas (some legumes and vegetables like broccoli, cauliflower, cabbage, and Brussels sprouts).
  • Talk to your doctor or health-care professional about taking probiotics.


National Institute of Diabetes and Disgestive and Kidney Diseases. "Irritable Bowel Syndrome (IBS)."

Wald, A. MD. "Patient information: Irritable bowel syndrome (Beyond the Basics)." UpToDate. Updated: Aug 12, 2015.

Abraczinskas, D. MD. "Patient information: Gas and bloating (Beyond the Basics)." UpToDate. Updated: Jun 24, 2016.

Medically Reviewed by a Doctor on 1/23/2017

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