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17
ALBI GradeAlbumin-bilirubin liver function grade in HCCUKELD ScoreUK model for end-stage liver diseaseMELD-XIMELD excluding INR — for anticoagulated patientsWest Haven CriteriaHepatic encephalopathy gradingMilan CriteriaLiver transplant eligibility in hepatocellular carcinomaLI-RADS v2018 (CT/MRI)Liver observation category from size, APHE and major featuresBCLC StagingHepatocellular carcinoma stage and treatment allocationSimplified AIH CriteriaSimplified criteria for autoimmune hepatitisRevised Original AIH ScoreIAIHG 1999 comprehensive autoimmune hepatitis scoreSAAGSerum-ascites albumin gradient — cause of ascitesR FactorHepatocellular vs cholestatic pattern in liver injuryCLIF-C ACLFMortality prediction in acute-on-chronic liver failureKing's College CriteriaTransplant criteria in acute liver failureGALAD ScoreHCC detection from gender, age, AFP-L3, AFP and DCPMetroticket 2.0AFP-adjusted up-to-seven for HCC transplant eligibilityRUCAMCausality in drug- and herb-induced liver injuryBaveno VII CriteriacACLD, CSPH and sparing screening endoscopy

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8
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8
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Colorectal

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Functional GI

37
Bristol Stool ScaleStool form types 1–7 and colonic transitRome IV Criteria for IBSIrritable bowel syndrome diagnosis and subtypeFunctional ConstipationRome IV — two of six items, IBS excludedOpioid-Induced ConstipationRome IV — constipation tied to opioid therapyFunctional DiarrhoeaRome IV — loose stools without predominant painFunctional Bloating / DistensionRome IV — bloating without other bowel disorder criteriaUnspecified Functional Bowel DisorderRome IV — bowel symptoms fitting no other categoryCentrally Mediated Abdominal Pain (CAPS)Rome IV — continuous pain unrelated to gut eventsNarcotic Bowel SyndromeRome IV — opioid-induced hyperalgesia of the gutFaecal Incontinence (Rome IV)Rome IV — the criteria, and why nobody is askedFunctional Anorectal PainLevator ani, unspecified pain and proctalgia fugaxFunctional Defecation DisordersRome IV — dyssynergia and inadequate propulsionInfant RegurgitationRome IV — the happy spitter, and the alarm features that rule it outInfant ColicRome IV — recurrent unexplained crying in a well infant under 5 monthsInfant DyscheziaRome IV — straining before a soft stool, and why not to intervenePaediatric Functional ConstipationRome IV — two of six over one month, with overflow soiling as a criterionToddler's DiarrhoeaRome IV functional diarrhoea of childhood — painless, thriving childPaediatric Cyclic Vomiting SyndromeRome IV — both age bands, with different criteria for eachPaediatric Rumination SyndromeRome IV — infant and child/adolescent criteriaFunctional Nausea & Vomiting (Children)Rome IV — two separate disorders that can be met togetherAerophagiaRome IV — distension that increases through the dayPaediatric Functional DyspepsiaRome IV — four times a month, with PDS and EPS subtypingPaediatric Irritable Bowel SyndromeRome IV — plus the constipation clause clinicians missAbdominal MigraineRome IV — stereotypical incapacitating episodes weeks apartFunctional Abdominal Pain — NOSRome IV — the residual category, reached after the other threeNonretentive Faecal IncontinenceRome IV — soiling without retention, where laxatives make it worseFunctional DyspepsiaRome IV — with PDS and EPS subtypingRumination SyndromeRome IV — effortless regurgitation without retchingCyclic Vomiting SyndromeRome IV — stereotypical episodic vomitingCannabinoid HyperemesisRome IV — CVS pattern relieved by cannabis cessationChronic Nausea & VomitingRome IV — chronic nausea and vomiting syndromeBelching DisordersRome IV — supragastric vs gastric belchingFunctional HeartburnRome IV — heartburn with normal acid exposureReflux HypersensitivityRome IV — normal acid exposure, positive symptom associationFunctional Chest PainRome IV — non-cardiac, non-reflux chest painGlobusRome IV — painless lump-in-throat sensationFunctional DysphagiaRome IV — dysphagia with normal endoscopy and manometry
  1. Calculators
  2. /
  3. Rome IV Criteria for IBS
Functional GI

Rome IV Criteria for IBS

Irritable bowel syndrome diagnosis and subtype

Core criteria

Rome IV requires onset at least six months before diagnosis, with criteria fulfilled for the last three.

Onset over 50, rectal bleeding, unexplained weight loss, nocturnal symptoms, iron-deficiency anaemia, a family history of colorectal cancer or inflammatory bowel disease, or a palpable mass. Rome IV is a positive-diagnosis framework, but alarm features require investigation regardless.

Pain characteristics — at least two required

Subtyping

Assessed only on days with at least one abnormal bowel movement, and ideally recorded prospectively over two weeks.

Diagnostic criteria rather than a severity score. All of the timing requirements must be met, plus at least two of the three pain characteristics. Subtype is then assigned from stool form on days with abnormal bowel habit.

When to use
Use it when a patient presents with chronic abdominal pain and altered bowel habit and you want to make a positive diagnosis rather than a diagnosis of exclusion. It is designed for exactly that: Rome IV is a framework for saying what someone has, not for ruling out everything they might have. Check it after excluding alarm features, and alongside the small set of tests that distinguish irritable bowel syndrome from its common mimics. It is not appropriate for acute presentations, for patients with alarm features, or as a substitute for investigating a new change in bowel habit over the age of 50.
Why use it
Because 'no cause found' is a worse outcome for the patient than a named diagnosis, and it invites repeat investigation. Irritable bowel syndrome affects a large proportion of the population and has effective, subtype-specific treatments, but a patient told only what they do not have gets neither reassurance nor a treatment plan. Rome IV gives a positive definition, which means the diagnosis can be made confidently in primary care with limited testing, and it standardises entry criteria so that trial evidence is comparable across studies. The subtyping step matters practically: it is what decides whether the first prescription is a laxative or a bile-acid sequestrant.
Formula, evidence and interpretation

About the Rome IV Diagnostic Criteria for Irritable Bowel Syndrome

Rome IV diagnoses irritable bowel syndrome from recurrent abdominal pain on average at least one day per week over the last three months, with symptoms starting at least six months ago, plus at least two of three features: the pain is related to defecation, associated with a change in stool frequency, or associated with a change in stool form. Once met, the subtype is assigned from stool form on days with abnormal bowel habit — IBS-C, IBS-D, IBS-M or IBS-U. The key change from Rome III was tightening the pain frequency to weekly and dropping 'discomfort' as a qualifying symptom, which made the definition narrower and the diagnosed population smaller.

On this page

  • Formula
  • Interpreting the result
  • Inputs
  • What it returns
  • How it is calculated
  • Facts & figures
  • Evidence
  • How it compares
  • Pearls & pitfalls
  • Critical actions
  • Why it exists
  • About the creator
  • Limitations
  • If you are the patient
  • FAQ
  • Related calculators
  • References

Formula

IBS = (pain ≥ 1 day/week for 3 months) AND (onset ≥ 6 months ago) AND (≥ 2 of: related to defecation, change in stool frequency, change in stool form)
AND
All three clauses are required. Two of three pain characteristics without the frequency criterion does not meet Rome IV, and neither does weekly pain with only one characteristic.
≥ 2 of 3
Two is the threshold, not one. This is the most common scoring error in practice.
  • Rome IV removed 'abdominal discomfort' from the definition. Only pain qualifies, because 'discomfort' had no consistent meaning across languages and translations.
  • The subtyping proportions are calculated only over days with at least one abnormal bowel movement, not over all days.
  • Rome IV also defines separate bowel disorders — functional constipation, functional diarrhoea, functional abdominal bloating, unspecified functional bowel disorder — for patients who do not meet the IBS criteria. Not meeting IBS criteria does not mean nothing is wrong.

Interpreting the result

A met result supports a positive diagnosis and a subtype-directed treatment plan — it does not require further investigation in a patient without alarm features, and the guidelines are explicit about that. A not-met result is not a dead end: check the other Rome IV bowel disorders, since functional constipation and functional diarrhoea have overlapping but distinct criteria and a patient with no pain simply cannot have irritable bowel syndrome by definition. Treat the subtype as provisional rather than fixed; a substantial proportion of patients change subtype over a year, and IBS-M is the least stable of the four.

ScoreBandWhat it meansAction
IBS-CConstipation-predominantMore than 25% of movements Bristol 1–2, 25% or less Bristol 6–7Soluble fibre, osmotic laxatives, then secretagogues if needed
IBS-DDiarrhoea-predominantMore than 25% Bristol 6–7, 25% or less Bristol 1–2Loperamide; assess for bile-acid diarrhoea; consider rifaximin or eluxadoline
IBS-MMixedMore than 25% of both Bristol 1–2 and Bristol 6–7Treat the predominant symptom at the time; the least stable subtype over follow-up
IBS-UUnclassifiedCriteria met but no predominant stool patternRecheck with a prospective stool diary before settling on this
Not metCriteria not metTiming or pain-characteristic requirements unsatisfiedConsider the other Rome IV bowel disorders, or an organic cause

What the Rome IV Criteria for IBS needs (7 inputs)

Pain frequency — at least 1 day per week, last 3 months
Recurrent abdominal pain, averaged across the last three months. Rome III accepted three days per month and also accepted 'discomfort'; Rome IV requires weekly pain specifically, which is the single change that most reduced the number of patients meeting criteria.
Duration — onset at least 6 months ago
Symptoms must have begun at least six months before diagnosis, with the criteria fulfilled over the last three. This is what separates a chronic functional disorder from a post-infective or self-limiting episode.
Pain related to defecation
One of the three pain characteristics. Note that Rome IV says 'related to', not 'relieved by' — pain that worsens with defecation counts, which Rome III's wording arguably excluded.
Associated with a change in stool frequency
The second of the three pain characteristics.
Associated with a change in stool form or appearance
The third of the three pain characteristics.
Predominant stool form on abnormal days
Assessed using the Bristol Stool Form Scale, counting only days with at least one abnormal bowel movement. This is a proportion over time, so it needs a prospective record rather than recall.
Alarm features
Not part of the Rome IV criteria themselves, included here because a positive symptom profile does not make alarm features safe to ignore. Any present require investigation first.

Units. No units. All inputs are yes/no answers or a stool-form category; the only quantitative elements are the frequency and duration thresholds, which are fixed by the criteria at one day per week over three months and six months since onset.

What it returns

Criteria met or not met
Whether the timing requirements and at least two of the three pain characteristics are satisfied.
Subtype
IBS-C, IBS-D, IBS-M or IBS-U, from the stool-form distribution. The subtype, not the diagnosis, determines first-line treatment.
Alarm feature flag
Surfaced separately and prominently, because it changes the plan regardless of whether the criteria are met.

How it is calculated

Rome IV is consensus-derived rather than statistically fitted: an international committee synthesised the evidence and clinical experience to define each disorder, and the definitions are deliberately symptom-based because no biomarker distinguishes irritable bowel syndrome reliably. The structure is a conjunction of a timing rule and a symptom-cluster rule, which is what allows a positive diagnosis without imaging or endoscopy. The subtyping layer is bolted on separately and rests on the Bristol Stool Form Scale, because stool form tracks colonic transit and transit is what the main pharmacological treatments act on.

Facts & figures

What changed from Rome III to Rome IV
ElementRome IIIRome IV
Qualifying symptomPain or discomfortPain only
Pain frequencyAt least 3 days per monthAt least 1 day per week
Relationship to defecationImprovement with defecationRelated to defecation (worsening also counts)
SubtypesIBS-C, IBS-D, IBS-M, IBS-UUnchanged in name
Subtyping denominatorAll bowel movementsOnly days with an abnormal bowel movement

The net effect is a narrower definition. Studies applying both sets to the same population consistently find Rome IV identifies fewer patients, with a higher average symptom severity, than Rome III.

Minimum testing in suspected IBS without alarm features
TestWhat it excludes
Full blood countAnaemia suggesting an organic cause
Coeliac serologyCoeliac disease, which mimics IBS-D and IBS-M
Faecal calprotectinInflammatory bowel disease — the single most useful discriminator in younger patients
CRPInflammation, as an adjunct to calprotectin
Bile-acid testing (in IBS-D)Bile-acid diarrhoea, common and specifically treatable

Colonoscopy is not required to diagnose irritable bowel syndrome in a patient without alarm features and is not recommended routinely.

Rome II, III and IV side by side — why an older trial's population is not this one
ElementRome II (1999)Rome III (2006)Rome IV (2016)
Time frame≥ 12 weeks, not necessarily consecutive, in the preceding 12 months3 months, onset ≥ 6 months earlier3 months, onset ≥ 6 months earlier
Qualifying symptomAbdominal discomfort or painAbdominal pain or discomfortAbdominal pain only
Frequency thresholdNone stated beyond the 12-week rule≥ 3 days per month≥ 1 day per week
Associations required2 of 32 of 32 of 3
Relationship to defecationRelieved with defecationImprovement with defecationRelated to defecation — worsening also counts
Onset wording for stool changeOnset associated with a change in frequency or formOnset associated with a change in frequency or formAssociated with a change in frequency or form

Each revision narrowed the definition. A trial recruiting on Rome II or Rome III enrolled a broader, less symptomatic population than the same trial would today, which is worth remembering when older efficacy figures are quoted against a Rome IV clinic population.

Evidence

Derivation — Rome Foundation consensus, Rome IV

2016

Consensus criteria produced by the Rome Foundation's bowel-disorders committee and published in Gastroenterology in 2016, revising Rome III. Developed by expert committee with systematic literature review rather than fitted to a single cohort, which is the standard method for symptom-based functional definitions where no biomarker exists.

Rome IV is narrower than Rome III: the tightened pain-frequency threshold and the removal of 'discomfort' reduce the proportion of a given population meeting criteria, and those who do meet them have more severe symptoms on average.

Guideline adoption — American College of Gastroenterology

2021

The 2021 ACG clinical guideline on the management of irritable bowel syndrome adopts a positive-diagnosis strategy consistent with Rome IV, and recommends against routine colonoscopy in patients under 45 without alarm features.

The guideline endorses a positive diagnostic strategy over exhaustive exclusion, and specifically recommends checking coeliac serology and faecal calprotectin rather than broad testing.

How it compares

Rome IV Criteria for IBS vs Bristol Stool Form Scale

Not alternatives — Rome IV establishes the diagnosis and Bristol supplies the subtype, so the Rome IV assessment is incomplete without stool form.

Rome IV's symptom criteria decide whether a patient has irritable bowel syndrome. The subtyping step then counts the proportion of bowel movements at Bristol types 1–2 versus 6–7 on days with abnormal habit. Since the subtype is what determines first-line treatment, the Bristol distribution is doing real clinical work here rather than describing the result.

Open the Bristol Stool Form Scale calculator →

Rome IV Criteria for IBS vs Rome III criteria

Rome IV is the current standard and is deliberately narrower — a patient meeting Rome III may not meet Rome IV, and that is by design rather than a defect.

Rome IV raised the pain-frequency threshold from three days a month to one day a week, removed 'discomfort' as a qualifying symptom, and broadened 'improved by defecation' to 'related to defecation'. Populations assessed with both consistently show Rome IV identifying fewer patients with more severe average symptoms. For clinical care the practical implication is that patients displaced from the IBS label belong in one of the other Rome IV functional bowel disorders, not in no category at all.

Lacy BE, Mearin F, Chang L, et al. Bowel Disorders. Gastroenterology. 2016;150(6):1393-1407.

Rome IV Criteria for IBS vs Diagnosis by exclusion (colonoscopy-first)

A positive Rome IV diagnosis with targeted testing is the guideline-endorsed strategy; routine colonoscopy in young patients without alarm features is explicitly not recommended.

The exclusion-first approach subjects large numbers of patients to invasive testing with low yield, delays treatment, and leaves them with a diagnosis framed as an absence. The ACG guideline recommends a positive diagnostic strategy instead, with coeliac serology and faecal calprotectin doing most of the discriminating work. Colonoscopy remains indicated where alarm features are present or where calprotectin is raised.

Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Am J Gastroenterol. 2021;116(1):17-44.

Pearls & pitfalls

  • Two of the three pain characteristics are required, not one. This is the commonest scoring error.
  • 'Related to defecation' is broader than Rome III's 'improved by defecation' — pain that worsens on defecation counts.
  • Discomfort no longer qualifies. Rome IV requires pain, and a patient with bloating and altered habit but no pain does not have irritable bowel syndrome by this definition.
  • The subtyping denominator is days with an abnormal bowel movement, not all days. Using all days shifts patients toward IBS-U incorrectly.
  • Subtype is not stable. A large share of patients move between subtypes over a year, so revisit it rather than treating the first assignment as permanent.
  • A positive Rome IV profile does not override alarm features, and the criteria were never intended to.
  • Not meeting the criteria is a finding, not a failure — functional constipation, functional diarrhoea and functional bloating are separate Rome IV diagnoses with their own criteria.

Critical actions

  • Screen for alarm features first: onset over 50, rectal bleeding, unexplained weight loss, nocturnal symptoms, iron-deficiency anaemia, a family history of colorectal cancer or inflammatory bowel disease, or a palpable mass.
  • Check coeliac serology and faecal calprotectin as a minimum — both mimic irritable bowel syndrome, both are treatable, and neither is excluded by the symptom criteria.
  • In IBS-D, assess for bile-acid diarrhoea; it is common, frequently missed, and responds to sequestrants.
  • Obtain a prospective one- to two-week stool diary before assigning a subtype, since the rule is a proportion.
  • Give the diagnosis a name and explain it. A positive diagnosis reduces repeat investigation; 'nothing was found' increases it.
  • Review the subtype at follow-up rather than assuming it is fixed.

Why this score exists

The Rome process exists because functional gastrointestinal disorders had no agreed definitions, which made trials incomparable and left patients with a label that varied by clinician. Each revision has tightened the definitions, and the committee has been explicit that Rome IV was made deliberately narrower — the intent was to identify a more homogeneous group for research, accepting that some patients who would have qualified under Rome III now fall into the neighbouring functional bowel disorders instead. That is a design decision with a clinical consequence worth understanding: a patient who no longer meets IBS criteria under Rome IV has not been cured and has not been shown to have something else, and Rome IV provides other named disorders precisely so they are not left undiagnosed.

About the creator

  • Brian E. Lacy

    First author, Rome IV bowel disorders committee

    Chaired the committee that wrote the Rome IV criteria for irritable bowel syndrome and the other functional bowel disorders.

  • Robin Spiller

    Senior author

    Co-authored the Rome IV bowel disorders chapter and contributed much of the underlying post-infectious IBS evidence.

Limitations

  • Consensus-derived rather than fitted to outcome data, so it has no sensitivity or specificity against an objective reference standard — none exists for irritable bowel syndrome.
  • Entirely symptom-based, so it depends on the accuracy of the history and on the patient and clinician sharing a definition of pain.
  • The weekly pain threshold excludes patients with genuinely troublesome but less frequent symptoms, who then fall into the neighbouring functional disorders.
  • Subtype instability over time limits how much weight a single assignment should carry.
  • Developed largely in Western populations; symptom reporting and the acceptability of discussing bowel habit vary culturally, which affects how the criteria perform elsewhere.
  • Says nothing about severity, which drives management as much as subtype does and needs separate assessment.

If you are the patient

Irritable bowel syndrome is diagnosed by a specific pattern rather than by a test that comes back positive. Doctors look for tummy pain happening at least once a week over three months, starting at least six months ago, together with at least two of: the pain being connected to opening your bowels, a change in how often you go, or a change in what your stool looks like. If that pattern fits, you have a diagnosis — it is a real condition, not a case of nothing being found. Your doctor will usually also do a couple of blood tests and a stool test, because coeliac disease and inflammation of the bowel can look similar and are treated differently. You will then be given a subtype depending on whether you tend toward constipation, diarrhoea or both, and that is what decides which treatment is tried first. Keeping a diary of your stool type for a couple of weeks genuinely helps get this right. Do tell your doctor promptly about any bleeding, unexplained weight loss, or being woken at night by your symptoms — those need looking into separately.

Frequently asked questions

What are the Rome IV criteria for IBS?#

Recurrent abdominal pain on average at least one day per week in the last three months, with onset at least six months ago, associated with at least two of: pain related to defecation, a change in stool frequency, or a change in stool form or appearance.

How is Rome IV different from Rome III?#

Three changes. The pain-frequency threshold rose from at least three days per month to at least one day per week; 'abdominal discomfort' was removed so that only pain qualifies; and 'improved by defecation' became the broader 'related to defecation'. The result is a narrower definition that identifies fewer patients with more severe average symptoms.

What were the Rome II criteria for IBS?#

At least 12 weeks, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain with two of three features: relieved with defecation; onset associated with a change in stool frequency; onset associated with a change in stool form. There was no per-week or per-month frequency threshold at all — the 12-week rule did all the work — which made Rome II considerably broader than anything since.

What were the Rome III criteria for IBS?#

Recurrent abdominal pain or discomfort at least three days per month in the last three months, with onset at least six months previously, associated with two or more of: improvement with defecation; onset associated with a change in stool frequency; onset associated with a change in stool form. Rome III introduced the three-month and six-month structure that Rome IV kept, and added the first explicit frequency threshold.

Why does it matter which Rome version a trial used to recruit?#

Because each revision narrowed the definition, so the same trial run under Rome II, Rome III and Rome IV would enrol progressively smaller and more symptomatic populations. Efficacy figures quoted from Rome II or Rome III trials were generated in a broader, milder group than a Rome IV clinic population — which is worth keeping in mind when an older number is applied to the patient in front of you.

Do I need a colonoscopy to be diagnosed with IBS?#

Usually not. Rome IV is designed to support a positive diagnosis, and the ACG guideline recommends against routine colonoscopy in patients under 45 without alarm features. Coeliac serology and faecal calprotectin do most of the work of excluding the important mimics. Colonoscopy is indicated where alarm features are present or calprotectin is raised.

What are the IBS subtypes and how are they decided?#

IBS-C, IBS-D, IBS-M and IBS-U. They are assigned from the proportion of bowel movements at Bristol stool types 1–2 versus 6–7, counting only days with at least one abnormal bowel movement: more than 25% at types 1–2 gives IBS-C, more than 25% at 6–7 gives IBS-D, more than 25% of both gives IBS-M, and neither predominating gives IBS-U.

Can you have IBS without pain?#

Not under Rome IV. Pain is mandatory, and 'discomfort' was deliberately removed in this revision. A patient with bloating and altered bowel habit but no pain would be considered for one of the other Rome IV bowel disorders — functional constipation, functional diarrhoea, or functional abdominal bloating.

How many of the three pain characteristics do I need?#

At least two. Meeting only one does not satisfy Rome IV, even if the pain frequency and duration criteria are met. This is the most frequent scoring mistake.

Does the IBS subtype change over time?#

Frequently. A substantial proportion of patients shift between subtypes across a year, and IBS-M is the least stable. Reassess the subtype at follow-up rather than treating the initial assignment as permanent.

What if I meet some but not all of the Rome IV criteria?#

Then you may have a different Rome IV bowel disorder rather than nothing. Functional constipation, functional diarrhoea, functional abdominal bloating and unspecified functional bowel disorder all have their own criteria and overlap considerably with irritable bowel syndrome. Not meeting IBS criteria is a finding to act on, not a dead end.

Are the Rome IV criteria enough on their own?#

They establish the diagnosis but not the safety of it. Alarm features — onset over 50, bleeding, weight loss, nocturnal symptoms, iron-deficiency anaemia, relevant family history, a palpable mass — require investigation regardless of how well the symptom profile fits.

Related calculators

  • Stool Osmotic Gap — Osmotic vs secretory diarrhoea from stool electrolytes
  • Bristol Stool Scale — Stool form types 1–7 and colonic transit
  • SCCAI — Simple clinical colitis activity index — symptoms only
  • Boston Bowel Prep Scale — Colonoscopy preparation adequacy by segment
  • Functional Constipation — Rome IV — two of six items, IBS excluded
  • Functional Bloating / Distension — Rome IV — bloating without other bowel disorder criteria
  • Paediatric Irritable Bowel Syndrome — Rome IV — plus the constipation clause clinicians miss

References

Original / primary reference

  1. Lacy BE, Mearin F, Chang L, Chey WD, Lembo AJ, Simren M, Spiller R. Bowel Disorders. Gastroenterology. 2016;150(6):1393-1407 (Rome IV).

Clinical practice guidelines

  1. Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Am J Gastroenterol. 2021;116(1):17-44.

Superseded criteria — Rome II and Rome III

  1. Thompson WG, Longstreth GF, Drossman DA, Heaton KW, Irvine EJ, Müller-Lissner SA. Functional bowel disorders and functional abdominal pain. Gut. 1999;45(Suppl 2):II43-II47 (Rome II).
  2. Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC. Functional Bowel Disorders. Gastroenterology. 2006;130(5):1480-1491 (Rome III).

Other references

  1. Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol. 1997;32(9):920-924 (the Bristol scale used for subtyping).

Last updated August 1, 2026. Clinical knowledge base written and curated by GastroAGI Team from primary medical literature.

Written from primary literature and not yet independently clinically reviewed.

For use by qualified healthcare professionals. This calculator supports clinical judgement and does not replace it.