K58.0 vs K59.1
K58.0 (Irritable bowel syndrome with diarrhea) compared with K59.1 (Functional diarrhea), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. K59.1 carries an Excludes1 note covering K58.0: “irritable bowel syndrome with diarrhea (K58.0)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| K58.0Irritable bowel syndrome with diarrhea | K59.1Functional diarrhea | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | K00-K95 — Diseases of the Digestive System (K00-K95) | K00-K95 — Diseases of the Digestive System (K00-K95) |
| Definition | Irritable bowel syndrome with diarrhea is a billable ICD-10-CM diagnosis code (K58.0). | Functional diarrhea is a billable ICD-10-CM diagnosis code (K59.1). |
| Includes | irritable colon spastic colon | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources