IntroductionFunctional Bowel Disorders
Section snippets
Functional Bowel Disorders
Functional bowel disorders are functional gastrointestinal disorders with symptoms attributable to the middle or lower gastrointestinal tract. These include the IBS, functional bloating, functional constipation, functional diarrhea, and unspecified functional bowel disorder.
To separate these chronic conditions from transient gut symptoms, they must have occurred for the first time ≥6 months before the patient presents, and their presence on ≥3 days a month during the last 3 months indicates
Definition
IBS is a functional bowel disorder in which abdominal pain or discomfort is associated with defecation or a change in bowel habit, and with features of disordered defecation.
Epidemiology
Throughout the world, about 10%–20% of adults and adolescents have symptoms consistent with IBS, and most studies find a female predominance.1, 2, 3 IBS symptoms come and go over time, often overlap with other functional disorders,4 impair quality of life,5 and result in high health care costs.6
Definition
Functional bloating is a recurrent sensation of abdominal distention that may or may not be associated with measurable distention, but is not part of another functional bowel or gastroduodenal disorder.
Epidemiology
Most of the research on bloating has dealt with subjects who also have other functional gastrointestinal disorders; up to 96% of IBS patients report this symptom. Community surveys reveal that about 10%–30% of individuals report bloating during the previous year.64, 65 It is about twice as common
Definition
Functional constipation is a functional bowel disorder that presents as persistently difficult, infrequent, or seemingly incomplete defecation, which do not meet IBS criteria.
Subjective and objective definitions of constipation include (1) straining, hard stools or scybala (hard, inspissated stool), unproductive calls (“want to but cannot”), infrequent stools, or incomplete evacuation; (2) <3 bowel movements per week, daily stool weight <35 g/day, or straining >25% of the time; and (3)
Definition
Functional diarrhea is a continuous or recurrent syndrome characterized by the passage of loose (mushy) or watery stools without abdominal pain or discomfort.
Epidemiology
There are few studies in which functional diarrhea was specifically diagnosed as distinct from IBS-D, so it is impossible to provide a precise frequency. Unspecified diarrhea was reported by 9.6% of Minnesota residents86 and 4.8% of people throughout the United States87; however, its duration and frequency are uncertain. Although a common
C5. Unspecified Functional Bowel Disorder
Individual symptoms discussed in the previous sections are very common in the population. These occasionally lead to medical consultation, yet are unaccompanied by other symptoms that satisfy criteria for a syndrome. Such symptoms are best classified as unspecified.
Bowel symptoms not attributable to an organic etiology that do not meet criteria for the previously defined categories
C5. Diagnostic Criterion⁎ for Unspecified Functional Bowel Disorder
Future Research Directions
Development of the Rome Criteria is a continuing process, and the criteria should be updated as data allow. We suggest the following topics for research.
- 1
Perform long-term, longitudinal studies on patients with disorders of bowel function to better determine the natural history, specifically regarding changing severity and interchange among disorders and the predominant symptom.
- 2
Direct more research to patients in primary care.
- 3
Compare the efficacy of new drugs with that of older ones (eg,
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