K59: Other functional intestinal disorders
Codes under K59 (Other functional intestinal disorders). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.
| Code | Description | Billable |
|---|---|---|
| K59.0 | Constipation | — |
| K59.0 | Constipation | — |
| K59.00 | Constipation, unspecified | ✓ |
| K59.00 | Constipation, unspecified | ✓ |
| K59.01 | Slow transit constipation | ✓ |
| K59.01 | Slow transit constipation | ✓ |
| K59.1 | Functional diarrhea | ✓ |
| K59.1 | Functional diarrhea | ✓ |
| K59.02 | Outlet dysfunction constipation | ✓ |
| K59.02 | Outlet dysfunction constipation | ✓ |
| K59.2 | Neurogenic bowel, not elsewhere classified | ✓ |
| K59.2 | Neurogenic bowel, not elsewhere classified | ✓ |
| K59.03 | Drug induced constipation | ✓ |
| K59.03 | Drug induced constipation | ✓ |
| K59.3 | Megacolon, not elsewhere classified | — |
| K59.3 | Megacolon, not elsewhere classified | — |
| K59.04 | Chronic idiopathic constipation | ✓ |
| K59.04 | Chronic idiopathic constipation | ✓ |
| K59.4 | Anal spasm | ✓ |
| K59.4 | Anal spasm | ✓ |
| K59.8 | Other specified functional intestinal disorders | — |
| K59.8 | Other specified functional intestinal disorders | — |
| K59.09 | Other constipation | ✓ |
| K59.09 | Other constipation | ✓ |
| K59.9 | Functional intestinal disorder, unspecified | ✓ |
| K59.9 | Functional intestinal disorder, unspecified | ✓ |
| K59.31 | Toxic megacolon | ✓ |
| K59.31 | Toxic megacolon | ✓ |
| K59.39 | Other megacolon | ✓ |
| K59.39 | Other megacolon | ✓ |
| K59.81 | Ogilvie syndrome | ✓ |
| K59.81 | Ogilvie syndrome | ✓ |
| K59.89 | Other specified functional intestinal disorders | ✓ |
| K59.89 | Other specified functional intestinal disorders | ✓ |
Frequently asked questions
What is ICD-10-CM code K59?
K59 is an ICD-10-CM category covering Other functional intestinal disorders. It contains 34 more specific diagnosis codes, 28 of which are billable.
Is K59 a billable code?
No — K59 is a category header and isn't billable on its own. Code to the highest level of specificity using one of its subcodes (for example K59.0 — Constipation). 28 of the 34 codes under K59 are billable.
What codes fall under K59?
K59 includes K59.0, K59.0, K59.00, K59.00, K59.01, plus 29 more. See the full list with descriptions and billable status above.
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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
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