Five Categories of Lower Gastrointestinal Functional Bowel Disorders in Revised Rome IV Criteria
MAY 23, 2016
In contrast to the previous Rome III criteria, the new definition involves a change in the frequency of abdominal pain from at least 3 days per month now to at least 1 day per week during the past 3 months; this change is based on the latest data that suggest that abdominal pain occurs more frequently than previously recognized. Additionally, “improvement with defecation” has now been replaced by “related to defecation” to reflect the reality that many IBs patients do not experience improvement in their abdominal pain with defecation, but instead, may actually experience a worsening of abdominal pain.
With regard to functional constipation, the new criteria now specify that abdominal pain and/or bloating may be present but are not predominant symptoms, which supports the concept that functional constipation and IBS-C are disorders that exist on a continuous spectrum. A similar change was made for functional diarrhea. In addition, to reflect the latest data, the diagnostic criteria for functional diarrhea were changed to stipulate that >25%, rather than 75%, of stools are loose.
The definition of functional abdominal bloating/distension has been changed to add the phrase “abdominal fullness, pressure or a sensation of trapped gas” to more accurately reflect the symptoms that patients typically report. The change also helps to distinguish functional abdominal bloating, with an associated increase in abdominal girth, from more subjective symptoms of bloating.
The new criteria also reflect the use of new technologies, such abdominal plethysmography, and insights into the pathophysiology of distention. Finally, the guidelines now recognize that patients with functional abdominal bloating/distension may also report symptoms of mild abdominal pain a/or minor bowel movement abnormalities.
Finally, a separate category was created for opioid-induced constipation, which the committee felt should not be considered a distinct functional gastrointestinal disorder but instead should be categorized as an opioid-induced adverse event. Mearin noted that there may, however, frequently be overlap between the disorders; for example, functional constipation may overlap with or exacerbate OIC.