What is Diarrhea?

Diarrhea is defined as passing frequent and/or loose or watery stools. Acute diarrhea goes away in a few weeks, and becomes chronic when it lasts longer than 3–4 weeks. If no specific cause is found after a thorough investigation and certain criteria are met, a diagnosis of functional diarrhea may be considered.

What are Functional Bowel Disorders?

People with functional bowel disorders do not demonstrate physical or laboratory abnormalities to explain their gastrointestinal (GI) symptoms. One example of a functional bowel disorder is irritable bowel syndrome (IBS), which is estimated to affect approximately 10–15% of all adults.

Learn more about IBS

Is Functional Diarrhea the Same as Irritable Bowel Syndrome?

Individuals with functional diarrhea may represent a subgroup of people with IBS. People with IBS often report altered bowel habits, including diarrhea and/or constipation, associated with abdominal pain. Bloating, feeling an urgent need to use a bathroom, straining, or a sense of incomplete evacuation may also occur.  Many of these symptoms occur in persons with functional diarrhea but the absence of abdominal pain distinguishes these people from those with IBS.

How do Doctors Evaluate Patients with Functional Diarrhea?

The doctor will begin with asking about your medical history, including use of medicines and dietary habits, and performing a careful physical examination. Additional studies such as blood tests and stool analysis may be ordered.

Diagnostic procedures such as colonoscopy or endoscopy may be indicated, allowing the physician to examine the inner surface of the colon and small intestine to exclude other causes of chronic diarrhea, such as infections or inflammation of the colon or small intestinal diseases.

Working with Your Doctor

patient doctor

Successful relationships with healthcare providers are an important part of managing life with a long-term digestive disorder.

Doctor–Patient Communication

How to Help Your Doctor Help You

How to Talk to Your Doctor