ICD-10 Code K59.39 – Other Megacolon (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K59.39 – Other megacolon
What it is
K59.39 identifies megacolon that is not classified elsewhere. Use it for abnormal colonic dilation when the record supports a megacolon diagnosis but does not fit a more specific category.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include marked abdominal distention, constipation, and reduced bowel motility, with imaging or exam showing an enlarged colon.
When to use this code
Use K59.39 when the provider documents other megacolon and does not name Hirschsprung disease, toxic megacolon, or another more specific cause. It may also apply when the chart confirms megacolon but the etiology is not further specified. Check documentation if the note only says constipation or bowel obstruction without megacolon.
Do not use for
Do not use this code for toxic megacolon, congenital megacolon, or Hirschsprung disease when those diagnoses are documented. Also avoid it if the record supports only nonspecific constipation or abdominal distention.
Coding tip
Before assigning K59.39, look for the exact provider wording and any stated cause so you do not miss a more specific ICD-10-CM code.