K59.1
Billable codeFunctional diarrhea
The ICD-10 code for functional diarrhea is K59.1.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- K59.0Constipationnon-billable header
- K59.2Neurogenic bowel, not elsewhere classified
- K59.3Megacolon, not elsewhere classifiednon-billable header
- K59.4Anal spasm
- K59.8Other specified functional intestinal disordersnon-billable header
- K59.9Functional intestinal disorder, unspecified
- K59.1Functional diarrhea
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 5645
Associated MS-DRGs
K59.1 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.
Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.
- DRG 314Other Circulatory System Diagnoses with MCC
- DRG 315Other Circulatory System Diagnoses with CC
- DRG 316Other Circulatory System Diagnoses without CC/MCC
- DRG 391Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC
- DRG 392Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC