TABLE 1.

Summary of Rome I-IV criteria

Rome I. IBS criteria (from ref. 2)

Continuous or recurrent symptoms of:

1. Abdominal pain, relieved with defecation, or associated with a change in frequency or consistency of stool; AND/OR

2. Disturbed defecation (2 or more of): a. Altered stool frequency, b. Altered stool form (hard or loose/watery), c. Altered stool passage (straining or urgency, feeling of incomplete evacuation), d. Passage of mucus; USUALLY WITH

3. Bloating or feeling of abdominal distension.

Rome II criteria (from ref. 3)

Functional bowel disorders recognized: irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea, unspecified functional bowel disorder

IBS criteria: At least 12 wk, which need not be consecutive, in the preceding 12 mo of abdominal discomfort or pain that has 2 or 3 features:

1. Relieved with defecation; and/or

2. Onset associated with a change in frequency of stool; and/or

3. Onset associated with a change in form (appearance) of stool.

Rome II “Splitting” of non-IBS criteria: At least 12 wk, which need not be consecutive, in the preceding 12 mo of:

Functional abdominal bloating:

1. Feeling of abdominal fullness, bloating or visible distension; And

2. Insufficient criteria for a diagnosis of functional dyspepsia, IBS, or other functional disorder.

Functional constipation:

1. Straining; 2. Lumpy or hard stools 3. Sensation of incomplete evacuation 4. Sensation of anorectal obstruction/blockade in >1/4 defecations; 5. Manual maneuvers to facilitate >1/4 defecations (eg, digital, evacuation, support of the pelvic floor); and/or 6. <3 defecations/wk.

Loose stools are not present, and there are sufficient criteria for IBS.

Functional diarrhea:

1. Liquid (mushy) or watery stools;

2. Present > 3/4 of the time; and

3. No abdominal pain.

Rome III (from ref. 4)

Functional bowel disorders recognized: irritable bowel syndrome, functional bloating, functional constipation, functional diarrhea, unspecified functional bowel disorder.

IBS: Recurrent abdominal pain or discomfort (an uncomfortable sensation not described as pain) at least 3 days per month in the last 3 mo associated with 2 or more of the following:

1. Improvement with defecation

2. Onset associated with a change in frequency of stool

3. Onset associated with a change in form (appearance) of stool

Criteria fulfilled for the last 3 mo with symptom onset ≥6 mo prior to diagnosis.

Subtyping IBS by predominant stool pattern

IBS-C–hard or lumpy stools ≥25% and loose (mushy) or watery stools <25% of BMs

IBS-C–hard or lumpy stools ≥25% and loose (mushy) or watery stools <25% of BMs

IBS-D–loose (mushy) or watery stools ≥ 25% and hard or lumpy stool < 25% of BMs

IBS-M–hard or lumpy stools ≥ 25% and loose (mushy) or watery stools ≥ 25% of BMs

Unsubtyped IBS–insufficient abnormality of stool consistency to meet criteria for IBS-C, D, or M

Functional Constipation: must include ≥2 of:

Straining during ≥25% of defecations

Lumpy or hard stools in ≥25% of defecations

Sensation of incomplete evacuation for ≥25% of defecations

Sensation of anorectal obstruction for ≥25% of defecations

Manual maneuvers to facilitate ≥25% of defecations (eg, digital, evacuation, support of the pelvic floor)

<3 defecations per week

Loose stools are rarely present without the use of laxatives

Insufficient criteria for IBS

Functional Diarrhea

Loose (mushy) or watery stools without pain in ≥75% of stools

Criteria fulfilled for the last 3 mo with symptom onset ≥6 mo before diagnosis.

Rome IV Bowel Disorders (from ref. 5)

Functional bowel disorders recognized: irritable bowel syndrome, functional abdominal bloating/distension, functional constipation, functional diarrhea, unspecified functional bowel disorder, opioid-induced constipation

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

1. Related to defecation

2. Associated with a change in frequency of stool

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

Criteria fulfilled for the last 3 mo with symptom onset ≥6 mo before diagnosis.

Rome IV Bowel Disorders: Diagnostic Criteria for IBS Subtypes (from ref. 5)

Predominant bowel habits are based on stool form on days with at least 1 abnormal bowel movement.

IBS with predominant constipation (IBS-C)

>25% of BMs with Bristol Stool Form Scale (BSFS) types 1 or 2 and <25% of BMs with BSFS types 6 or 7

IBS with predominant diarrhea (IBS-D)

>25% of BMs with BSFS types 6 or 7 and <25% of BMs with BSFS types 1 or 2

IBS with mixed bowel habits (IBS-M)

>25% of BMs with BSFS types 1 or 2 and >25% of BMs with BSFS types 6 or 7

IBS unclassified (IBS-U)

Meets criteria for IBS, but BMs not accurately categorized into 1 of the 3 groups above.