Decoding Rome V: Key Updates in Adult and Pediatric Gut-Brain Interaction Disorders

Disorders of gut-brain interaction (DGBI)—formerly classified as functional gastrointestinal disorders—affect over 40% of the population globally. Diagnosing these conditions presents a unique clinical challenge: because DGBI pathophysiology stems from dysregulated neuro-gastroenterological signaling, visceral hypersensitivity, altered motility, immune activation, and central-microbiome interactions rather than structural or biochemical biomarkers detectable on routine endoscopy or imaging, clinical care relies heavily on standardized, criteria-congruent symptom profiling.

Introduction: The Evolution of DGBI Diagnosis

To operationalize expert-consensus criteria into objective, reproducible clinical tools, the Rome Foundation periodically updates its diagnostic questionnaires. The publication detailing the Development of the Rome V Diagnostic Questionnaires (Gastroenterology, May 2026) marks a critical milestone in neurogastroenterology. Authored by the 7-member Rome V Questionnaire Committee, comprising GI psychologists, pediatric gastroenterologists, and adult GI motility experts, this major update refines diagnostic precision, resolves long-standing psychometric limitations in symptom frequency scaling, harmonizes pediatric and adult assessment tools across the lifespan, and introduces significant diagnostic expansions, including 3 new adult and 14 new pediatric DGBI entities.

For practicing physicians, pediatricians, nurse practitioners, and clinical researchers, understanding the scientific rationale, structural changes, and epidemiological impacts of the Rome V questionnaires is vital for accurate clinical decision-making, differential diagnosis, patient communication, and research design.

Why It Matters

Precision, Rationale, and Lifespan Alignment

The transition from Rome IV to Rome V is a structural advancement in how clinical symptom data are captured, quantified, and validated across diverse global populations.

Resolving Psychometric Flaws in Symptom Frequency Scaling

A primary driver for revising the adult questionnaire was correcting structural limitations identified in the legacy Rome IV 9-point symptom frequency scale. In Rome IV, two critical response options combined multiple frequency steps: “2 to 3 times a month” and “2 to 3 times a week”. In epidemiological and clinical practice, this combined formatting introduced significant psychometric distortions:

• Diagnostic Threshold Mismatches: The Rome IV criteria for Functional Dyspepsia (FD) required symptoms occurring at least 3 days per week. However, because the response scale grouped 2 and 3 days into a single option, scoring algorithms were forced to approximate, inadvertently qualifying patients with only 2 days of weekly symptoms and inflating false-positive rates.
• Artificial Response “Humps”: Combining frequency steps created artificial prevalence spikes at the grouped options when plotting population data, distorting parametric statistical modeling.
• Timeframe Shift Confusion: The legacy scale switched abruptly from monthly metrics (“days per month”) to weekly metrics (“once per week”) at a pivotal diagnostic threshold, causing cognitive ambiguity for respondents.

To overcome these barriers, the committee conducted testing comparing three response formats in 2,000 adults. While a 0-to-30 day recall scale produced heavy cognitive bias toward mental anchor numbers (10, 15, 20, 25, and 30 days), a newly modified 9-point frequency scale successfully eliminated statistical humps, provided clear single-day intervals, and established a smooth, logical progression:

The Refined Rome V 9-Point Symptom Frequency Scale: 0: Never, or less than 1 day a month | 1: 1 day a month | 2: 2 days a month | 3: 3 days a month 4: 4 days a month (once a week on average) | 5: 2 days a week | 6: 3 days a week 7: Most days (4 to 6 days a week) | 8: Every day

Standardizing Localization with Anatomical Visual Maps

Differentiating epigastric pain from heartburn, or biliary colic from generalized abdominal distress, frequently presents linguistic and cultural hurdles during clinical interviews. To enhance diagnostic precision, Rome V incorporates standardized anatomical diagrams directly into the questionnaires—3 figures in the adult questionnaire and 4 in the pediatric versions. These visual maps explicitly demarcate epigastric pain, epigastric burning, abdominal pain, and biliary pain, significantly improving response fidelity.

Methodological Rigor: Pre-Publication Multinational Validation

Rather than conducting post-hoc validation years after publication, the committee executed prospective validation surveys prior to finalizing the Rome V criteria. Encompassing 30,000 adults across 15 countries (Argentina, Canada, China, France, Germany, Japan, South Korea, Mexico, Poland, Romania, Spain, Sweden, Turkey, UK, and USA) and 7,724 pediatric cases across 4 global regions (China, Italy, Mexico, and USA), this proactive approach allowed researchers to test scoring algorithms, confirm comprehension, and eliminate unexpected prevalence artifacts before official release.

Lifespan Harmonization: Pediatric-to-Adult Continuity

In Rome IV, pediatric instruments utilized disparate scales (e.g., 0–5 for bowel symptoms vs. 0–4 for upper GI disorders), impeding long-term tracking as pediatric patients transitioned to adult care. Rome V harmonizes pediatric symptom frequency scales with the adult modified 9-point format. This structural alignment enables seamless longitudinal tracking of DGBI trajectories from infancy through adolescence and into adulthood.

Who It Affects

Clinical Specialties, Populations, and Trialists

The updates in Rome V directly impact primary care physicians, pediatricians, specialist gastroenterologists, behavioral health specialists, and clinical researchers.

Adult Gastroenterology and Primary Care Practice

In adult populations, overall DGBI prevalence remains stable at 42.2% (compared to 40.3% in Rome IV), with an identical female-to-male odds ratio of 1.66. However, substantial prevalence shifts occur within individual condition categories:

• Irritable Bowel Syndrome (IBS): Global IBS prevalence effectively doubled from 4.1% in Rome IV to 8.9% in Rome V. This increase is directly driven by intentional criteria changes: lowering the minimum abdominal pain frequency threshold from 1 day per week to 3 days per month, and reincorporating the term “discomfort” into the core diagnostic criteria. Clinicians will see significantly more patients meeting formal diagnostic criteria for IBS.
• Fecal Incontinence (FI): Prevalence rose from 1.6% to 4.2%, reflecting the adjustment of the diagnostic threshold from 2 episodes per month down to 1 episode per month, providing greater clinical sensitivity to mild or early-stage bowel control impairment.
• Opioid-Induced Constipation (OIC): Prevalence fell sharply from 1.6% down to 0.2% due to refined questionnaire wording requiring explicit self-report of opioid medications rather than generic pain prescriptions.
• Cannabinoid Hyperemesis Syndrome (CHS): Detected prevalence increased to 0.6% (up from 0.05%), reflecting neutral questioning that reduces patient non-disclosure alongside rising global cannabis use.

Pediatricians and Pediatric Gastroenterologists

The pediatric framework underwent an unprecedented expansion. Expanding from 13 conditions in Rome IV to 27 distinct pediatric DGBI entities in Rome V, the new instruments provide tailored assessment across three age-specific formats:

1. Infant/Toddler Parent-Report (Ages 0–3): 18 items assessing feeding duration, regurgitation, excessive crying, and infant distress.
2. Child/Adolescent Parent-Report (Ages 4–17): Comprehensive caregiver reporting across upper and lower GI domains.
3. Child/Adolescent Self-Report (Ages 10–17): Direct patient reporting written at an age-appropriate reading level.

In epidemiological testing of 7,724 children, Rome V rates aligned closely with historical benchmarks: IBS was identified in 2.1% (matching global literature ~3%), Chronic Constipation in 17.1% (matching pooled estimates ~14.1%), and Functional Dyspepsia divided into Epigastric Pain Syndrome (1.7%) and Postprandial Distress Syndrome (5.5%).

Clinical Researchers and Regulatory Bodies

Regulatory agencies such as the US FDA and European Medicines Agency (EMA) require standardized, validated instruments for clinical trial endpoints in DGBI drug development. Rome V provides the required diagnostic rigor and case-definition stability necessary for multi-center clinical trials.

What Changes

New Adult DGBI Entities in Rome V

The adult questionnaire expanded from 86 to 114 questions to incorporate 3 new diagnostic entities:

• Abdominal Migraine (Adult): Captures paroxysmal episodes of severe abdominal pain with associated systemic symptoms. Epidemiological testing revealed a high global prevalence of 5.3%, establishing it as a major adult DGBI.
• Inability to Belch Syndrome: Retrograde cricopharyngeal dysfunction preventing belching, leading to thoracic/abdominal distension and gurgling noises; identified in 1.5% of adults.
• Narcotic Bowel Syndrome: Severe abdominal pain worsening despite escalating opioid doses; identified in 0.08%.

14 New Pediatric DGBI Entities

Pediatric DGBIs were reclassified by anatomic region (Upper GI vs. Lower GI & Gallbladder) and expanded to include 14 new diagnoses:

1. Anticipatory Restrictive Feeding
2. Hypersensitive Dysphagia
3. Hunger Dysregulation: Excess Hunger Drive
4. Hunger Dysregulation: Reduced Hunger Drive
5. Medically Triggered Feeding Disorder
6. Reflux Hypersensitivity
7. Reflux Negative Pain Disorder
8. Centrally Mediated Abdominal Pain Syndrome
9. Cannabinoid Hyperemesis Syndrome
10. Infant Distress Syndrome
11. Supragastric Belching Syndrome
12. Functional Abdominal Bloating
13. Biliary Pain Syndrome
14. Proctalgia Fugax

The Pediatric FICAI Severity Matrix

To evaluate disease burden beyond binary diagnosis, the pediatric committee created the FICAI classification system (Frequency, Intensity, Chronicity, Impact). Developed via Delphi consensus, FICAI establishes a 4-parameter severity profile:

| Severity Tier | Frequency (d/wk) | Intensity (Pain 1–10) | Chronicity (Months) | Impact on Life | | --- | --- | --- | --- | --- | | Mild | 1 – 2 days/week | 1 – 3 (Mild) | 2 – 5 months | $< 4\\text{ times / month}$ | | Moderate | 3 – 5 days/week | 4 – 6 (Moderate) | 6 – 12 months | $4\\text{ times/mo} – 4\\text{ times/wk}$ | | Severe | 6 – 7 days/week | 7 – 10 (Severe) | $> 12\\text{ months}$ | $> 4\\text{ times / week}$ |

Note: In pediatric Chronic Constipation, “Incontinence” replaces “Intensity”. While FICAI is not required for meeting core diagnostic criteria, it provides a standardized framework for specialist referral, monitoring therapeutic efficacy, and clinical research stratification.

Comparative Summary: Rome IV vs. Rome V Questionnaires

| Parameter | Rome IV Version | Rome V Version | Clinical Significance | | --- | --- | --- | --- | | Adult Question Count | 86 questions | 114 questions | Incorporates new diagnoses & context items | | Adult DGBI Diagnosed | 22 disorders | 25 disorders | Adds Abdominal Migraine, Inability to Belch, Narcotic Bowel | | Pediatric DGBI Diagnosed | 13 disorders | 27 disorders | $+14$ new entities across feeding, esophageal & lower GI | | Symptom Frequency Scale | Grouped steps (2-3 d/mo, 2-3 d/wk) | Modified 9-point scale with distinct steps | Eliminates statistical humps & improves precision | | Anatomical Visual Aids | None | 3 adult & 4 pediatric visual maps | Enhances anatomical localization accuracy | | Global IBS Prevalence | 4.1% | 8.9% | Reflects lower pain threshold (3 d/mo) & “discomfort” term | | Pediatric Severity Tool | None | FICAI Framework | Standardized clinical severity & impact profiling |

Clinical Takeaways for Everyday Practice

For healthcare providers, the Rome V questionnaires represent a major advance in diagnostic precision. Key actionable steps include:

1. Anticipate Higher IBS and FI Identification: Criteria changes will classify a broader clinical cohort under formal IBS (8.9%) and Fecal Incontinence (4.2%), enabling earlier treatment initiation.
2. Screen Adults for Abdominal Migraine: Given its 5.3% global prevalence, episodic severe abdominal pain accompanied by nausea or migraine features should prompt evaluation for adult abdominal migraine and consideration of neuromodulatory therapies.
3. Utilize Visual Maps in Clinic: Incorporating anatomical diagrams during intake helps clarify epigastric versus biliary pain.
4. Implement FICAI in Pediatrics: Utilizing Frequency, Intensity, Chronicity, and Impact profiling assists subspecialty referral and progress monitoring.

By integrating rigorous psychometrics with international field validation, Rome V provides clinicians with the clarity needed to accurately diagnose and manage gut-brain interaction disorders across the lifespan.

Reference

1. Palsson OS, Lacy BE, Benninga MA, et al. Development of the Rome V Diagnostic Questionnaires. Gastroenterology. 2026;170(6):1408-1416. doi:10.1053/j.gastro.2026.01.041