ICD-10 Code K51.0 – Ulcerative (chronic) pancolitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.0 – Ulcerative (chronic) pancolitis
What it is
K51.0 identifies chronic ulcerative colitis involving the entire colon. Use it when documentation states pancolitis, diffuse colitis, or ulcerative colitis affecting the full large intestine.
Clinical signs
Typical findings include chronic bloody diarrhea, abdominal pain, urgency, and rectal bleeding. Endoscopy or pathology may show continuous colonic inflammation; clinical features vary, so refer to documentation.
When to use this code
Use K51.0 when the provider clearly documents ulcerative pancolitis or ulcerative colitis with pan-colonic involvement. It also fits follow-up visits for established disease when the condition remains active or is being monitored. If the record only says ulcerative colitis without extent, check documentation.
Do not use for
Do not use this code for Crohn disease, infectious colitis, or ischemic colitis. Also avoid it when the chart does not confirm involvement of the entire colon.
Coding tip
Code the documented extent of ulcerative colitis; if pancolitis is not stated, query or check documentation before assigning K51.0.