Excludes1 pair
K52.9 vs K59.1
K52.9 and K59.1 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on K52.9
functional diarrhea (K59.1)
K52.9
Noninfective gastroenteritis and colitis, unspecified
BillableUnspecified
- Chapter 11
- Diseases of the digestive system
- Section
- K50-K52
Use when the record says
- Colitis NOS
- Enteritis NOS
- Gastroenteritis NOS
- Ileitis NOS
- Jejunitis NOS
- Sigmoiditis NOS
Indexed under
- Cecitis
- Colitis (acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
- Enteritis (acute) (diarrheal) (hemorrhagic) (noninfective)
- Enterocolitis
- Gastroenteritis (acute) (chronic) (noninfectious)
K59.1
Functional diarrhea
Billable
- Chapter 11
- Diseases of the digestive system
- Section
- K55-K64
Indexed under
- Diarrhea, diarrheal › functional
- Diarrhea, diarrheal › neurogenic
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027