Functional diarrhea

This code represents chronic or recurrent diarrhea without an identifiable organic cause. It is characterized by frequent loose or watery stools, often associated with abdominal discomfort, and is considered a functional gastrointestinal disorder. The diagnosis is typically made after ruling out infectious, inflammatory, and malabsorptive etiologies.

Use this code when documentation clearly indicates a diagnosis of functional diarrhea, often after a thorough workup has excluded other causes. This applies to patients experiencing chronic diarrheal symptoms that do not meet criteria for Irritable Bowel Syndrome with Diarrhea (IBS-D) or other specific diarrheal syndromes. Supporting documentation should include physician notes detailing the absence of structural or biochemical abnormalities.

• Do not use this code if a specific organic cause for the diarrhea (e.g., infection, inflammatory bowel disease, malabsorption) has been identified.
• Differentiate from Irritable Bowel Syndrome with Diarrhea (IBS-D); functional diarrhea lacks the characteristic abdominal pain relief with defecation seen in IBS.
• Ensure documentation specifies "functional" or "idiopathic" diarrhea to support the use of this code, indicating a diagnosis of exclusion.