ICD-10 Code K51.30 – Ulcerative (chronic) rectosigmoiditis without complications (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.30 – Ulcerative (chronic) rectosigmoiditis without complications
What it is
This code identifies chronic ulcerative colitis limited to the rectosigmoid region, without documented complications. It is used when the record specifies rectosigmoid involvement and does not note bleeding, obstruction, fistula, or other complications.
Clinical signs
Typical findings include chronic inflammation of the rectum and sigmoid colon, with symptoms such as diarrhea, rectal urgency, abdominal discomfort, or blood in stool. Clinical features vary; refer to documentation.
When to use this code
Use K51.30 when the provider documents ulcerative rectosigmoiditis and explicitly states that it is chronic and uncomplicated. It also fits follow-up visits for known disease when the same diagnosis is confirmed without new complications. If the note is vague, check documentation before coding.
Do not use for
Do not use this code for ulcerative colitis limited to other bowel segments or for cases with documented complications. If the record does not specify rectosigmoid involvement, check documentation.
Coding tip
Confirm both the anatomic site and the absence of complications in the provider note before assigning K51.30.