Rome IV Criteria. What Type of IBS Do You Have?

Identify Your IBS Subtype

Irritable Bowel Syndrome is a Functional Bowel Disorder meaning there is no diagnostic test.

Blood tests, stool samples and radiological scans may have been arranged by your Doctor although these are to rule out other conditions such as Coeliac, Crohns, Colitis and Cancer.

Diagnosing IBS is dependent on the profile of presenting symptoms.  For example – bloating / constipation / diarrhoea / pain.

With no way of diagnosing IBS, assessing symptoms can be vague when a patient complains of bloating or diarrhoea.

Fortunately a diagnostic criteria exists for Irritable Bowel Syndrome, another reason to thank the Romans.

IBS is not a new disorder affecting people today with busy lifestyles and convenience foods.

It’s highly likely that people have been suffering from IBS for centuries.

In 1989 a group of Physicians got together in Italy and decided to lay down some criteria for diagnosing IBS- the Rome Criteria was born.

The Rome Criteria outlines the frequency, and duration of specific symptoms aiding in the diagnosis if IBS.

Over the years the criteria has been adapted with a total of 4 being published.

Rome I Criteria- 1989

Rome II Criteria- 1999

Rome III Criteria- 2006

The most recent version being Rome VI Criteria May 2016.

Don’t worry if you were diagnosed before the new criteria were published.

Rome criteria are used globally to diagnose IBS and little is changed other than the wording in the latest revision.

The recent update is more accommodating to terminology rather than symptoms.


Diagnostic Criteria for Irritable Bowel Syndrome

Recurrent abdominal pain, on average, at least 1 day per week in the last 3 months, associated with 2 or more of the following criteria:

See also  Understanding Irritable Bowel Syndrome

1.       Related to defecation

2.       Associated with change in frequency of stool

3.       Associated with change in form (appearance) of stool.

Criteria fulfilled for the last 3 months with symptom onset at least 6 months before diagnosis.


The criteria states symptoms must be persistent at least 1 day per week within the last 3 months and over 6 months since onset.

Short lived symptoms of travel diarrhoea or food poisoning would not fit the Rome Criteria.

The symptom profile of IBS can vary between individual.  The prominence of IBS symptoms can categorise sufferers into 1 of the three main subgroups including:

1.       Diarrhoea Predominant (IBS-D)

2.       Constipation Predominant (IBS-C)

3.       Mixed Predominance (IBS-M)

IBS with predominant constipation: More than onefourth (25%) of bowel movements with Bristol stool form types 1 or 2 and less than one-fourth (25%) of bowel movements with Bristol stool form types 6 or 7. Alternative for epidemiology or clinical practice: Patient reports that abnormal bowel movements are usually constipation (like type 1 or 2 in the picture of Bristol Stool Form Scale (BSFS), see Figure 2A).

IBS with predominant diarrhea (IBS-D): more than onefourth (25%) of bowel movements with Bristol stool form types 6 or 7 and less than one-fourth (25%) of bowel movements with Bristol stool form types 1 or 2. Alternative for epidemiology or clinical practice: Patient reports that abnormal bowel movements are usually diarrhea (like type 6 or 7 in the picture of BSFS, see Figure 2A).

IBS with mixed bowel habits (IBS-M): more than on fourth (25%) of bowel movements with Bristol stool form types 1 or 2 and more than one-fourth (25%) of bowel movements with Bristol stool form types 6 or 7. Alternative for epidemiology or clinical practice: Patient reports that abnormal bowel movements are usually both constipation and diarrhea (more than one-fourth of all the abnormal bowel movements were constipation and more than one-fourth were diarrhea, using picture of BSFS, see Figure 2A).

See also  The Cost of Common Constipation

IBS unclassified (IBS-U): Patients who meet diagnostic criteria for IBS but whose bowel habits cannot be accurately categorized into 1 of the 3 groups above should be categorized as having IBS unclassified. For clinical trials, subtyping based on at least 2 weeks of daily diary data is recommended, using the “25% rule.” a IBS subtypes related to bowel habit abnormalities (IBSC, IBS-D, and IBS-M) can only be confidently established when the patient is evaluated off medications used to treat bowel habit abnormalities.