Table 3.

Rome IV Irritable Bowel Syndrome-Subtypes Criteria

IBS Subtype	Criteria
IBS-C	More than one-fourth (25%) of bowel movements with Bristol Stool Scale Types 1–2 and less than one-fourth (25%) with Types 6–7.
IBS-D	More than one-fourth (25%) of bowel movements with Bristol Stool Scale Types 6–7 and less than one-fourth (25%) with Types 1–2.
IBS-M	More than one-fourth (25%) of bowel movements with Bristol Stool Scale Types 1–2 and more than one-fourth (25%) with Types 6–7.
IBS-U	Patients meet diagnostic criteria for IBS but their bowel habits cannot be accurately categorized in any of the above subtypes.

IBS, irritable bowel syndrome; IBS-C, IBS with predominant constipation; IBS-D, IBS with predominant diarrhea; IBS-M, IBS with mixed bowel habits; IBS-U, unclassified IBS.