K51.20

HCC Category Mapping

What This Code Means

A chronic inflammatory condition limited to the rectum (the lowest part of the colon) without any complications. This is the simplest form of ulcerative proctitis.

Coding Tips

• •Confirm that inflammation is limited to the rectum only; if it extends higher, use a different code
• •Verify no complications are present; if any complications exist, use K51.21x codes instead

Clinical Significance

Ulcerative proctitis without complications is the mildest and most limited form of ulcerative colitis, confined to the rectum. Despite its limited extent, it still represents a chronic inflammatory condition requiring ongoing monitoring, as approximately 10-30% of patients may progress to more extensive disease over time.

Documentation Requirements

• ✓Confirmed diagnosis of ulcerative colitis limited to the rectum via colonoscopy
• ✓Biopsy results consistent with ulcerative colitis histology
• ✓Documentation that inflammation does not extend beyond the rectosigmoid junction
• ✓Statement confirming absence of complications (no bleeding, obstruction, fistula, or abscess)
• ✓Current treatment plan (typically topical aminosalicylates such as mesalamine suppositories)
• ✓Disease activity assessment and surveillance plan

Commonly Confused Codes