ICD-10 Code K55.21 – Angiodysplasia of colon with hemorrhage (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K55.21 – Angiodysplasia of colon with hemorrhage
What it is
K55.21 identifies angiodysplasia in the colon with active or documented bleeding. It refers to fragile, abnormal blood vessels in the large intestine that can cause gastrointestinal hemorrhage.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe lower gastrointestinal bleeding, such as hematochezia or occult blood loss, with endoscopic evidence of colonic angiodysplasia.
When to use this code
Use K55.21 when the provider documents colonic angiodysplasia and specifies hemorrhage or bleeding. It also applies when the bleeding source is confirmed in the colon and tied to angiodysplasia.
Choose this code only when the hemorrhage is part of the diagnosis, not merely suspected. Check documentation if the note mentions gastrointestinal bleeding without a confirmed colonic source.
Do not use for
Do not use K55.21 for angiodysplasia without hemorrhage or for bleeding from another gastrointestinal site. If the record is unclear, check documentation.
Coding tip
Confirm both the colonic location and the hemorrhage in the provider note before assigning K55.21.