ICD-10 Code K51.511 – Left sided colitis with rectal bleeding (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.511 – Left sided colitis with rectal bleeding
What it is
K51.511 identifies ulcerative colitis limited to the left side of the colon, with rectal bleeding documented. Use it when the record clearly links both the colitis location and bleeding.
Clinical signs
Typical findings include bloody diarrhea, urgency, abdominal cramping, and inflammation involving the descending colon, sigmoid colon, or rectum. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents left-sided ulcerative colitis and rectal bleeding in the same encounter. It also fits follow-up visits when the diagnosis remains active and the bleeding is still part of the documented condition.
If the chart only says colitis, ulcerative colitis, or rectal bleeding separately, you should not assume this code. Check documentation for the exact disease type and anatomic extent.
Do not use for
Do not use K51.511 for Crohn disease, infectious colitis, or nonspecific proctitis. Do not use it when rectal bleeding is documented without confirmed left-sided ulcerative colitis.
Coding tip
Confirm both the left-sided extent and the bleeding in the provider note before assigning K51.511.