ICD-10 Code K51.21 – Ulcerative (chronic) proctitis with complications (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.21 – Ulcerative (chronic) proctitis with complications
What it is
This code identifies ulcerative proctitis, a form of ulcerative colitis limited to the rectum, when complications are documented. Use it when the record shows chronic rectal inflammation plus a complication, not uncomplicated disease.
Clinical signs
Typical findings include rectal bleeding, urgency, mucus passage, and tenesmus. Clinical features vary; refer to documentation for the specific complication, such as bleeding, obstruction, or other recorded disease effects.
When to use this code
Use K51.21 when the provider documents ulcerative proctitis with a complication and the condition is chronic. It may appear in problem lists, endoscopy reports, or assessment notes that clearly link the complication to ulcerative proctitis. Check documentation if the complication is not specified.
Do not use for
Do not use this code for uncomplicated ulcerative proctitis, ulcerative colitis limited to other bowel segments, or nonspecific rectal inflammation. If the record does not confirm a complication, code the condition documented instead.
Coding tip
Always capture the documented complication and verify that the note states ulcerative proctitis, not a different inflammatory bowel diagnosis.