There is some evidence that, despite attempts to classify them separately, functional bowel disorders are not distinct entities and that such divisions are artificial.
Dr Ford and colleagues from the United Kingdom examined this issue in a large cohort of secondary care patients.
Consecutive, unselected adults with gastrointestinal (GI) symptoms attending out-patient clinics at 2 hospitals in Hamilton, Ontario were recruited.
Demographic data, symptoms and presence of anxiety, depression or somatization were collected prospectively.
|1 in 5 chronic idiopathic constipation patients reported abdominal pain|
|Alimentary Pharmacology & Therapeutics|
The research team used validated questionnaires, including the Rome III questionnaire, with patients categorized as having irritable bowel syndrome (IBS), functional diarrhea or chronic idiopathic constipation.
The team compared data between these disorders, and measured degree of overlap between them by suspending their mutual exclusivity.
Of 3656 patients providing complete lower GI symptom data, 42% met criteria for a functional bowel disorder.
Diarrhea-predominant IBS patients were younger, and more were female, met criteria for anxiety, and reported somatization-type behavior, compared with functional diarrhea.
The team reported that only loose, mushy or watery stools were more common in functional diarrhea.
When mutual exclusivity was suspended, overlap occurred in 28%.
Constipation-predominant IBS patients were younger, and more were female, had never married, reported anxiety type symptoms and exhibited somatization-type behavior.
The research team observed that 1 in 5 chronic idiopathic constipation patients reported abdominal pain or discomfort.
All constipation symptoms were more common in constipation-predominant IBS.
When the mutual exclusivity was suspended, overlap occurred in 18%.
Dr Ford's team concluded, "There were significant differences in demographics between individuals with functional bowel disorders."
"Despite this, the Rome III classification system falls short of describing unique entities."