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Functional GI Disorders

Functional gastrointestinal (GI) and motility disorders are the most common GI disorders in the general population. Estimates vary, but about 1 in 4 people or more in the U.S. have one of these disorders.[1,2] The conditions account for about 40% of GI problems seen by doctors and therapists.[2]

The term "functional" is generally applied to disorders where the body's normal activities in terms of the movement of the intestines, the sensitivity of the nerves of the intestines, or the way in which the brain controls some of these functions is impaired. However, there are no structural abnormalities that can be seen by endoscopy, x-ray, or blood tests. Thus it is identified by the characteristics of the symptoms and infrequently, when needed, limited tests. The Rome diagnostic criteria categorize the functional gastrointestinal disorders and define symptom based diagnostic criteria for each category.[3]

Functional esophageal disorders

a sensation of a lump, something stuck, or a tightness in the throat
Functional chest pain
the feeling of chest pain, presumably of esophageal origin (can be confused with cardiac pain which must be examined)
Functional heartburn
persistent burning sensation in the absence of gastroesophageal reflux disease (GERD), a motility disorder, or a structural explanation
Functional dysphagia
the sensation of difficulty swallowing

Functional gastroduodenal disorders (symptoms generally attributable to the mid or upper gastrointestinal tract)

Functional dyspepsia
pain or discomfort located in the upper abdomen
repetitive air swallowing or ingesting air and belching
Functional vomiting
recurrent vomiting in the absence of all known medical and psychiatric causes
Rumination syndrome
effortless regurgitation of recently swallowed food

Functional bowel disorders and abdominal pain (symptoms generally attributable to the mid or lower gastrointestinal tract)

Irritable bowel syndrome (IBS)
a group of bowel disorders characterized by abdominal discomfort or pain associated with defecation or a change in bowel habit. 
Functional abdominal bloating
a group of functional bowel disorders dominated by a feeling of abdominal fullness or bloating
Functional constipation
a group of functional disorders characterized by persistent difficult, infrequent, or seemingly incomplete defecation.  
Functional diarrhea
continuous or recurrent passage of loose or watery stools without abdominal pain

Functional abdominal pain

Functional abdominal pain
continuous or frequently recurrent abdominal pain, either not or infrequently related to gut function, and associated with some loss of daily activities

Functional disorders of the biliary tract and pancreas (symptoms generally attributable to the upper or upper right abdomen)

Gall bladder dysfunction
characterized by episodes of severe steady pain accompanied by decreased gall bladder emptying
Sphincter of Oddi dysfunction
a motility disorder characterized by severe steady pain with no structural abnormalities that explain the symptoms. It sometimes occurs following gall bladder removal, but also may occur with an intact gall bladder.

Functional disorders of the anus and rectum

Functional fecal incontinence
recurrent uncontrolled passage of fecal material where no structural or neurological cause is evident
Functional anorectal pain
Levator ani syndrome is a dull ache in the rectum that lasts for hours to days. Proctalgia fugax is an infrequent sudden, severe pain in the anal area of short duration
Functional defecation disorders
Dyssynergic defecation or inadequate defecatory propulsion

Functional disorders: neonate and toddlers

Infant regurgitation
uncomplicated involuntary return (regurgitation) of stomach contents into the mouth. Common and normal in infants.
Infant rumination syndrome
voluntary, habitual regurgitation of recently swallowed stomach contents. Rare.
Cyclic vomiting syndrome
recurrent episodes of intense nausea and vomiting lasting hours to days separated by symptom-free intervals lasting weeks to months.
Infant colic
long bouts of crying or irritability without obvious cause.
Functional diarrhea
daily, painless, recurrent passage of 3 or more large, unformed stools for at least 4 weeks in infancy or preschool years.
Infant dyschezia
straining and crying with stool passage.
Functional constipation
infrequent, painful, hard, or large diameter bowel movements.

Functional disorders: children and adolescents

Vomiting and aerophagia
adolescent rumination syndrome, cyclic vomiting syndrome, aerophagia
Abdominal pain-related functional GI disorders
functional dyspepsia, irritable bowel syndrome (IBS), abdominal migraine, childhood functional abdominal pain
Constipation and incontinence
functional constipation, non-retentive fecal incontinence


  1. Talley NJ. Functional gastrointestinal disorders as a public health problem. Neurogastroenterol Motil. 2008 May;20 Suppl 1:121-129.

  2. Parkman HP, Doma S. Importance of gastrointestinal motility disorders. Practical Gastroenterology. September 2006.

  3. Drossman DA, et al. Rome III, the functional gastrointestinal disorders. Gastroenterology. April 2006 Volume 130 Number 5.
Last modified on February 16, 2015 at 02:55:49 PM