Irritable Bowel Syndrome
International diagnostic criteria, Rome IV, released May 2016

Recurrent abdominal pain at least 1 day/week in the last
3 months associated with two or more of the following:
1. Related to defecation
2. change in frequency of stool
3. change in form (appearance) of stool
* Criteria fulfilled for the last 3 months with symptom onset
at least 6 months prior to diagnosis


Information about a November 2021 modification to allow for faster diagnosis of IBS:


Our mission is to improve the lives of people with Disorders of Gut-Brain Interaction. The Rome Foundation is an independent not for profit 501(c) 3 organization that provides support for activities designed to create scientific data and educational information to assist in the diagnosis and treatment of Disorders of Gut-Brain Interaction (DGBIs), formerly called Functional Gastrointestinal Disorders (FGIDs)

For almost three decades, the Rome organization has sought to legitimize and update our knowledge of the DGBIs. This has been accomplished by bringing together scientists and clinicians from around the world to classify and critically appraise the science of gastrointestinal function and dysfunction. This knowledge permits clinical scientists to make recommendations for diagnosis and treatment that can be applied in research and clinical practice.

The Rome Foundation is committed to the continuous development, legitimization and preservation of the field of DGBIs through science-based activities. We are inclusive and collaborative, patient-centered, innovative and open to new ideas.  (From the Rome Foundation website. Quoted with permission)

Rome Foundation Website and Resources

International functional GI experts finalized Rome IV, the first major update to the Rome criteria since 2006, in December 2014 in Rome, Italy. Rome IV was published in the journal Gastroenterology in May 2016 and officially presented to the gastroenterology professional community at the Digestive Disease Week conference in San Diego, California, USA on May 21-25, 2016. Rome V is currently under development and expected to be released in 2026,

by Douglas A. Drossman, MD, MACG of the Drossman Center for the Education and Practice of Biopsychosocial Care, the University of North Carolina and the Rome Foundation. Gastroenterology, May 2016.

Update on Rome IV Criteria for Colorectal Disorders: Implications for Clinical Practice.

by Magnus Simren, MD, University of Gothenburg,  Gothenburg, Sweden, Olafur S. Palsson, PsyD and William E. Whitehead, PhD, both from the Center for Functional GI and Motility Disorders, University of North Carolina, Chapel Hill, NC, USA.  Current Gastroenterology Reports, April 2017


From the IBS Impact blog:

New Rome IV Diagnostic Criteria for Irritable Bowel Syndrome Unveiled May 2016 (June 9, 2016)

New Rome IV Diagnostic Criteria for Irritable Bowel Syndrome Will Include Individualized Clinical Profiles,  (October 11, 2015)

“Behind the Scenes at Rome IV Foundation” Video Humanizes Functional GI Experts, (February 23, 2015)

Other important information on the nature of IBS, symptoms, diagnosis and standards of medical care can be found in the sections below. Pages often also include additional links to good quality, evidence-based information on a variety of IBS/functional GI issues

University of North Carolina/Chapel Hill Center for Functional GI and Motility Disorders


IFFGD International Foundation for Gastrointestinal Disorders

IBS Symptoms

IBS Impact blog post Irritable Bowel Syndrome (IBS) Is Not a Diagnosis of Exclusion


IBS Impact blog post An Evolving Redefinition of Severity in Irritable Bowel Syndrome (IBS)


IBS Impact blog post 15 Common Misconceptions That Shouldn’t Exist About Irritable Bowel Syndrome (IBS)


IBS Impact blog post Irritable Bowel Syndrome (IBS) and the Myth of a Cure


National professional organization guidelines for the diagnosis and/or treatment of IBS

In the United States:  American College of Gastroenterology –  December 2020

American Gastroenterological Association— November 2014

In Canada: Canadian Association of Gastroenterology– April 2019

In the United Kingdom:  British Society of Gastroenterology– April 2021

National Institute for Health and Clinical Excellence–April 2017

 British Dietetic Association,  Updated 2016

In Australia: National Prescribing Service, Medicine Wise, Australian Prescriber  (private non-profit, consumer centered, evidence-based entity)-2018

Gastroenterological Society of Australia (GESA) guidance for general practitioners. IBS4GPs.com

In New Zealand: Best Practices Advocacy Centre, New Zealand (BPACnz, private non-profit organization)-2014

Articles or abstracts from leading international researchers on important prevalence, diagnosis, symptom or treatment issues.

Irritable Bowel Syndrome: Theory vs. Reality  (original article 2009, updated 2017)

Brennan M.R. Spiegel, MD, MSHS

2007 IFFGD Research Award Recipient

then at VA Greater Los Angeles Health System and David Geffen School of Medicine, UCLA, now at Cedars-Sinai Health System and UCLA

The article states that Rome international diagnostic criteria for IBS, based on symptoms, are considered to be 98% accurate. Extensive testing of all people with potential IBS is unnecessary and discouraged, and is usually appropriate only for a few subgroups at higher risk of different GI disorders. Unfortunately studies show that health care providers in local communities are much more likely than IBS/functional GI specialists to still believe erroneously that IBS is a diagnosis of exclusion requiring many tests to rule out other conditions.

IBS – Beyond the Bowel: The Meaning of Co-existing Medical Problems

Olafur S. Palsson, Psy.D. and William E. Whitehead, Ph.D.
UNC Center for Functional GI & Motility Disorders

The Prevalence of Rome IV Functional Bowel Disorders Among Adults in the United States, Canada, and the United Kingdom   

Olafur S. Palsson , PsyD, University of North Carolina Center for Functional GI and Motility Disorders, USA, William E. Whitehead , PhD, University of North Carolina Center for Functional GI and Motility Disorders, USA  Hans Törnblom , MD, PhD, University of Gothenburg, Sweden, Ami D. Sperber , MD, MSPH, Ben-Gurion University of the Negev, Israel, and Magnus Simrén , MD, PhD, University of North Carolina Center for Functional GI and Motility Disorders, USA and University of Gothenburg, Sweden.  Gastroenterology, April 2020 (full-text)

The Prevalence and Impact of Overlapping Rome IV-Diagnosed Functional Gastrointestinal Disorders on Somatization, Quality of Life, and Healthcare Utilization: A Cross-Sectional General Population Study in Three Countries

Imran Aziz , MBChB, MD, University of Gothenburg, Sweden, Olafur S. Palsson , PsyD, University of North Carolina Center for Functional GI and Motility Disorders, USA,  Hans Törnblom , MD, PhD, University of Gothenburg, Sweden, Ami D. Sperber , MD, MSPH, Ben-Gurion University of the Negev, Israel,  William E. Whitehead , PhD, University of North Carolina Center for Functional GI and Motility Disorders, USA and Magnus Simrén , MD, PhD, University of Gothenburg, Sweden.

 American Journal of Gastroenterology, January 2018. Abstract only.

There are many conditions that fall along the spectrum of functional gastrointestinal disorders, also known as disorders of gut-brain interaction. Irritable bowel syndrome (IBS) is the most common condition in this category. This large study conducted in the United States, Canada and the United Kingdom  found that approximately a third of adults meet Rome IV criteria for a functional GI disorder, and approximately a third of that subset have two or more functional GI disorders.

Highlights of the Updated Evidence-Based Treatment Monograph
Gastroenterology and Hepatology, November 2018 interview with:

Eamonn M. M. Quigley, MD, the David M. Underwood Chair of Medicine in Digestive Disorders at Houston Methodist Hospital and Professor of Medicine at Weill Cornell Medical College, Houston, Texas, USA and a member of the American College of Gastroenterology Task Force responsible for the monograph, which was published in the American Journal of Gastroenterology, June 2018. Interview is open access.  The full monograph is available through open access on the American Journal of Gastroenterology site.

Last update to IBS page and all links verified March 2024