Diagnostic Criteria for Functional Gastrointestinal Disorders

Introduction to Rome Criteria

The Rome criteria define irritable bowel syndrome (IBS) as recurrent abdominal pain occurring at least 1 day per week in the last 3 months, associated with two or more of: pain related to defecation, change in stool frequency, or change in stool form, according to the American Gastroenterological Association 1, 2

The Manning criteria, a precursor to the Rome criteria, established six key symptoms for IBS diagnosis, including abdominal pain relieved by defecation, looser stools with onset of pain, and more frequent stools with onset of pain, as recommended by the European Society of Gastrointestinal Motility 3, 4
The Rome I criteria required at least three months of recurrent symptoms, including abdominal pain/discomfort relieved with defecation, or associated with change in stool frequency/consistency, according to the American College of Gastroenterology 3, 4
The Rome II criteria required 12 weeks of abdominal discomfort/pain with two of three features, including relieved by defecation, associated with change in frequency of stool, and associated with change in consistency of stool, as recommended by the World Gastroenterology Organisation 3, 5
The Rome III criteria modified the timeframe, requiring symptoms to have originated 6 months prior to diagnosis and been active for the past 3 months, according to the European Society of Gastrointestinal Motility 5, 6
The Rome IV criteria, the current standard, require recurrent abdominal pain at least 1 day/week in the last 3 months, with symptom onset at least 6 months before diagnosis, associated with two or more of related to defecation, associated with change in stool frequency, and associated with change in stool form/appearance, as recommended by the American Gastroenterological Association 1, 7

The Rome IV criteria are more restrictive than the Rome III criteria, resulting in lower prevalence estimates, with a global prevalence of 4.1% vs 10.1%, according to the World Gastroenterology Organisation 1, 2
Up to 50% of patients who met Rome III criteria may not meet Rome IV criteria, being reclassified as having other functional bowel disorders, as reported by the American College of Gastroenterology 1
The Rome IV criteria identify patients with more severe symptoms and higher psychological comorbidity, according to the European Society of Gastrointestinal Motility 1, 2

The initial assessment should evaluate for "red flags" that warrant further investigation, including weight loss, rectal bleeding, anemia, and nocturnal symptoms, as recommended by the American Gastroenterological Association 5, 8
Supportive clinical features include female predominance, age <45 years with symptoms >2 years, and history of frequent healthcare visits for non-gastrointestinal complaints, according to the European Society of Gastrointestinal Motility 3, 6
Diagnostic testing should be limited, with stool Hemoccult and complete blood count recommended as baseline, and sigmoidoscopy considered if colonic symptoms are present, as recommended by the American College of Gastroenterology 3, 5, 8

IBS is further classified into subtypes based on predominant stool pattern, including IBS with constipation, IBS with diarrhea, mixed IBS, and unsubtyped IBS, according to the World Gastroenterology Organisation 9

The Rome criteria were initially developed for research purposes, not clinical practice, though they have evolved to be more clinically applicable, as reported by the American Gastroenterological Association 3
Symptoms often fluctuate over time, and subtype classification may change, according to the European Society of Gastrointestinal Motility 9
Functional disorders frequently overlap with each other, complicating diagnosis, as reported by the American College of Gastroenterology 8
Once a functional diagnosis is established, the incidence of new non-functional diagnoses is extremely low, according to the European Society of Gastrointestinal Motility 3