ICD-10 Code K51.213 – Ulcerative (chronic) proctitis with fistula (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.213 – Ulcerative (chronic) proctitis with fistula
What it is
K51.213 identifies chronic ulcerative proctitis, meaning long-term inflammation limited to the rectum, when a fistula is also documented. Use it when the provider clearly links the fistula to ulcerative disease.
Clinical signs
Typical findings include rectal inflammation with bleeding, urgency, mucus, or tenesmus. A fistula may be noted on examination, imaging, or operative report; clinical features vary, so refer to documentation.
When to use this code
Use this code when the record states ulcerative proctitis is chronic and specifies a fistula. It is appropriate for confirmed ulcerative colitis limited to the rectum with fistulizing disease. If the fistula type or cause is unclear, check documentation before assigning the code.
Do not use for
Do not use K51.213 for nonspecific proctitis, Crohn’s disease, or ulcerative colitis without fistula. If the chart only mentions a suspected fistula or another anorectal disorder, check documentation.
Coding tip
Confirm both the ulcerative proctitis and fistula are documented together; if either element is missing, query or code more specifically.