The Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGDs) are disorders of the digestive system in which symptoms cannot be explained by the presence of structural or tissue abnormality. FGDs lack identifiable biomarkers, and therefore, like all functional disorders, FGDs are diagnosed based on their symptom picture.

In the past, FGDs were considered to be diagnoses of exclusion, meaning that they could only be diagnosed after organic (identifiable) disease was ruled out. However, back in 1988, a group of researchers and physicians met to devise strict criteria for the diagnosis of the various FGDs. These criteria are now known as the "Rome Criteria." Currently, these criteria are in their fourth revision as of 2016.

Here is a comprehensive list of FGDs as delineated by the Rome III criteria:

Functional Esophageal Disorders

• Functional heartburn
• Functional chest pain of presumed esophageal origin
• Functional dysphagia
• Globus

Functional Gastroduodenal Disorders

• Functional dyspepsia (includes postprandial distress syndrome and epigastric pain syndrome
• Aerophagia
• Unspecified excessive belching
• Chronic idiopathic nausea
• Functional vomiting
• Cyclic vomiting syndrome
• Rumination syndrome in adults

Functional Bowel Disorders

• Irritable bowel syndrome (IBS)
• Functional constipation
• Functional diarrhea
• Unspecified functional bowel disorder

Functional Abdominal Pain Syndrome

• Functional abdominal pain (FAP)

Functional Gallbladder and Sphincter of Oddi Disorders

• Functional gallbladder disorder
• Functional biliary Sphincter of Oddi disorder
• Functional pancreatic Sphincter of Oddi disorder

Functional Anorectal Disorders

• Functional fecal incontinence
• Functional Anorectal Pain (includes chronic proctalgia, Levator ani syndrome), unspecified functional anorectal pain, and proctalgia fugax)
• Functional Defecation Disorders (includes dyssynergic defecation and inadequate defecatory propulsion)

Childhood Functional GI Disorders: Infant/Toddler

• Infant regurgitation
• Infant rumination syndrome
• Cyclic vomiting syndrome
• Infant colic
• Functional diarrhea
• Infant dyschezia
• Functional constipation

Childhood Functional GI Disorders: Child/Adolescent

• Vomiting and Aerophagia: adolescent rumination syndrome, cyclic vomiting syndrome, and aerophagia
• Abdominal Pain-Related Functional GI Disorders: functional dyspepsia, IBS, abdominal migraine, childhood functional abdominal pain, and childhood functional abdominal pain syndrome
• Constipation and Incontinence: functional constipation and nonretentive fecal incontinence

Although the Rome criteria allow the diagnosis of FGDs to be symptom-based, your doctor may still want to run some standard diagnostic tests to rule out other diseases or to look for structural problems that are resulting in your symptoms. 

Although no visible signs of disease or structural problems are identified as causing the symptoms of FGDs, this does not mean that these disorders are not real, nor does it mean that they are not treatable. If you suspect you have or have been diagnosed with an FGD, it will be essential to work with your doctor on a working treatment plan. Treatment options may include:

• Medication
• Dietary changes
• Biofeedback
• Physical therapy
• Stress management
• Psychotherapy