ICD-10 Code K51.812 – Other ulcerative colitis with intestinal obstruction (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.812 – Other ulcerative colitis with intestinal obstruction
What it is
This code identifies ulcerative colitis, a chronic inflammatory bowel disease, when the record also documents intestinal obstruction. Use it for ulcerative colitis that is not otherwise specified as a more exact subtype.
Clinical signs
Typical findings include chronic diarrhea, abdominal pain, rectal bleeding, and signs of bowel blockage such as distention, nausea, vomiting, or reduced stool passage. Clinical features vary; refer to documentation.
When to use this code
Use K51.812 when the provider documents ulcerative colitis and intestinal obstruction in the same encounter. This applies whether the obstruction is described as partial or complete, if the record supports obstruction. Code the documented colitis type as “other” when no more specific ulcerative colitis category is stated.
Do not use for
Do not use this code if the record does not support intestinal obstruction or if the diagnosis is Crohn disease, infectious colitis, or another non-ulcerative cause. Check documentation.
Coding tip
Confirm both conditions are documented by the provider, and code the obstruction only when it is clearly linked to ulcerative colitis.