Functional GI Disorders

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.[1]

Functional esophageal disorders

Globus

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

Aerophagia

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, nonretentive fecal incontinence