K59.3 ICD-10-CA code: Megacolon, not elsewhere classified
K59.3 is the ICD-10-CA code for “Megacolon, not elsewhere classified” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
K59.3Megacolon, not elsewhere classified
Short description: Megacolon not elsewhere classified
ICD-10-CA · Canada · Also written K593
Index terms
Entries in CIHI’s alphabetical index that lead to K59.3. Searching the index by the condition the note names is how coders reach this code.
- Megasigmoid
- Macrosigmoid
- Dilatation, cecum
- Dilatation, colon
- Dilatation, rectum
- Hypertrophy, hypertrophic, cecum
- Hypertrophy, hypertrophic, colon
- Hypertrophy, hypertrophic, sigmoid
- Excess, excessive, excessively, large, colon
- Megacolon (acquired) (functional) (not Hirschsprung's disease) (in)
- Megacolon (acquired) (functional) (not Hirschsprung's disease) (in), toxic NEC
Notes for K59.3
As CIHI prints them, with any note K59.3 takes from the headings above it.
Includes
- Dilatation of colonToxic megacolon
Use additional code
Add a code for this detail when the note documents it.
- Use additional external cause code (Chapter XX) to identify toxic agent.
Excludes
Conditions classified elsewhere.
- Megacolon (due to) (in):• Chagas' disease (B57.3)• Clostridium difficile (A04.7)• congenital (aganglionic) (Q43.1)• Hirschsprung's disease (Q43.1)
- Change in bowel habit NOS (R19.4)functional disorders of stomach (K31.-)intestinal malabsorption (K90.-)psychogenic intestinal disorders (F45.3)From K59 Other functional intestinal disorders
- Certain:• conditions originating in the perinatal period (P00-P96)• infectious and parasitic diseases (A00-B99)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 11: Diseases of the digestive system (K00-K93)
Where K59.3 sits
- 1ChapterChapter 11: Diseases of the digestive system (K00-K93)
- 2Block K55-K64Other diseases of intestines
- 3Category K59Other functional intestinal disorders
- 4Valid code K59.3Megacolon, not elsewhere classified
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code K59.3 mean?
K59.3 is the ICD-10-CA code for “Megacolon, not elsewhere classified” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is K59.3 in ICD-10-CA?
K59.3 sits under K59 Other functional intestinal disorders, within K55-K64 Other diseases of intestines, within Chapter 11: Diseases of the digestive system (K00-K93).
What coding notes apply to K59.3?
ICD-10-CA lists Includes, Use additional code, Excludes notes for K59.3, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.