Other functional intestinal disorders (K59) ICD-10-CM
The K59 code range covers other functional intestinal disorders with 18 ICD-10-CM diagnosis codes. 14 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- functional disorders of stomach K31
Codes in the K59 Range 18 codes · 14 billable
- K59 Other functional intestinal disordersNon-billable
- K59.0 ConstipationNon-billable
- K59.00 Constipation, unspecified
- K59.01 Slow transit constipation
- K59.02 Outlet dysfunction constipation
- K59.03 Drug induced constipation
- K59.04 Chronic idiopathic constipation
- K59.09 Other constipation
- K59.1 Functional diarrhea
- K59.2 Neurogenic bowel, not elsewhere classified
- K59.3 Megacolon, not elsewhere classifiedNon-billable
- K59.31 Toxic megacolon
- K59.39 Other megacolon
- K59.4 Anal spasm
- K59.8 Other specified functional intestinal disordersNon-billable
- K59.81 Ogilvie syndrome
- K59.89 Other specified functional intestinal disorders
- K59.9 Functional intestinal disorder, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the K59 range.
Constipation
Infrequent or difficult evacuation of FECES. These symptoms are associated with a variety of causes, including low DIETARY FIBER intake, emotional or nervous disturbances, systemic and structural disorders, drug-induced aggravation, and infections.
Megacolon
Dilatation of the COLON, often to alarming dimensions. There are various types of megacolon including congenital megacolon in HIRSCHSPRUNG DISEASE, idiopathic megacolon in CONSTIPATION, and TOXIC MEGACOLON.
Megacolon, Toxic
An acute form of MEGACOLON, severe pathological dilatation of the COLON. It is associated with clinical conditions such as ULCERATIVE COLITIS; CROHN DISEASE; AMEBIC DYSENTERY; or CLOSTRIDIUM ENTEROCOLITIS.
Neurogenic Bowel
Loss or absence of normal intestinal function due to nerve damage or birth defects. It is characterized by the inability to control the elimination of stool from the body.
About the K59 Code Range
Functional intestinal disorders are problems with how the intestines work. This category includes constipation, diarrhea, bowel problems related to nerves, an enlarged colon, and anal spasm.
K59.0 divides constipation into slow transit, outlet dysfunction, drug-induced, chronic idiopathic, other, and unspecified forms. Chronic idiopathic means long-lasting with no known cause. K59.1 names functional diarrhea, while K59.2 names neurogenic bowel, a bowel problem related to nerves. K59.3 separates toxic megacolon from other megacolon. K59.4 names anal spasm. Other specified disorders under K59.8 include Ogilvie syndrome; K59.9 is for an unspecified functional intestinal disorder.
Questions About This Page
How many billable codes are in the K59 range?
Of the 18 codes in this range, 14 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the K59 range classify?
The range classifies other functional intestinal disorders. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
