ICD-10 Codes for Stool Disorders
The appropriate ICD-10 code for a stool disorder depends on the specific type of condition, with K59.0 (Constipation) and K59.1 (Functional diarrhea) being the most commonly used codes for general stool disorders.
Common ICD-10 Codes for Stool Disorders
Functional Bowel Disorders
- K59.0 - Constipation
- K59.1 - Functional diarrhea
- K59.2 - Neurogenic bowel, not elsewhere classified
- K59.3 - Megacolon, not elsewhere classified
- K59.4 - Anal spasm
- K59.8 - Other specified functional intestinal disorders
- K59.9 - Functional intestinal disorder, unspecified
Irritable Bowel Syndrome
- K58.0 - Irritable bowel syndrome with diarrhea
- K58.1 - Irritable bowel syndrome with constipation
- K58.2 - Mixed irritable bowel syndrome
- K58.9 - Irritable bowel syndrome without diarrhea
Coding Algorithm for Stool Disorders
Determine if the disorder is related to Irritable Bowel Syndrome:
- If IBS is diagnosed based on Rome criteria 1, use K58.x codes
- For IBS with predominant diarrhea: K58.0
- For IBS with predominant constipation: K58.1
- For mixed IBS: K58.2
- For IBS without diarrhea: K58.9
For non-IBS stool disorders:
- For constipation: K59.0
- For functional diarrhea: K59.1
- For neurogenic bowel disorders: K59.2
- For megacolon: K59.3
- For anal spasm: K59.4
- For other specified functional intestinal disorders: K59.8
- For unspecified functional intestinal disorders: K59.9
For inflammatory bowel disease-related stool disorders:
- For Crohn's disease: K50.x (with appropriate 4th and 5th characters)
- For ulcerative colitis: K51.x (with appropriate 4th and 5th characters)
Important Considerations
Diagnostic Criteria
When coding for IBS, ensure the diagnosis meets established criteria. According to Rome III criteria 1, IBS is diagnosed when a patient has:
- Recurrent abdominal pain or discomfort at least 3 days per month in the last 3 months
- Associated with two or more of:
- Improvement with defecation
- Onset associated with change in stool frequency
- Onset associated with change in stool form
Documentation Requirements
For accurate coding, medical documentation should include:
- Specific symptoms (frequency, consistency, associated pain)
- Duration of symptoms (at least 6 months for chronic conditions)
- Any diagnostic tests performed
- Exclusion of other conditions with similar presentations
Common Pitfalls
- Avoid using unspecified codes (K59.9) when more specific information is available
- Don't confuse functional disorders with inflammatory conditions (IBD vs. IBS)
- Document symptom patterns clearly to distinguish between constipation-predominant, diarrhea-predominant, or mixed patterns
- Consider comorbid conditions that may affect coding (e.g., diverticular disease, colorectal cancer)
Special Populations
For pediatric patients, consider using:
- R19.4 - Change in bowel habit
- R19.5 - Other fecal abnormalities
- P76.0 - Transitory ileus of newborn
For accurate coding and proper reimbursement, always document the specific characteristics of the stool disorder, including frequency, consistency, associated symptoms, and impact on daily functioning 2.