Functional GI disorders

Functional dyspepsia

Functional dyspepsia is a term for recurring symptoms of an upset stomach that have no obvious cause. Functional dyspepsia also is called non-ulcer dyspepsia.

Functional dyspepsia is common. It is a constant condition but symptoms don’t happen all the time. Symptoms resemble those of an ulcer. They include pain or discomfort in the upper abdomen, bloating, belching and nausea.


Symptoms of functional dyspepsia may include:

When to see a doctor

Make an appointment with your health care provider if you experience persistent symptoms that worry you.

Seek medical attention right away if you experience:


No one knows what causes functional dyspepsia. Health care providers consider it a functional disorder. That means it can’t be explained by a medical condition, so routine testing may not show any problems or causes. As a result, the diagnosis is based on symptoms.

Functional Bowel disorder

A functional bowel disorder (FBD) is a functional gastrointestinal disorder with symptoms attributable to the mid or lower gastrointestinal tract, including the irritable bowel syndrome (IBS), functional abdominal bloating, functional constipation, functional diarrhea, and unspecified functional bowel disorder.

Irritable bowel syndrome

IBS comprises a group of functional bowel disorders in which abdominal discomfort or pain is associated with defecation or a change in bowel habit, and with features of disordered defecation.


The following symptoms cumulatively support the diagnosis of IBS:

These symptoms can be used to subclassify patients with predominant diarrhea or constipation

Functional abdominal bloating

Functional abdominal bloating comprises a group of functional bowel disorders which are dominated by a feeling of abdominal fullness or bloating and without sufficient criteria for another functional gastrointestinal disorder.

Functional constipation

Functional constipation comprises a group of functional disorders which present as persistent difficult, infrequent or seemingly incomplete defecation.

Functional diarrhea

Functional diarrhea is continuous or recurrent passage of loose or watery stools without abdominal pain.