K51.313
BillableUlcerative (chronic) rectosigmoiditis with fistula
HCC Category Mapping
V28HCC 81 — Ulcerative Colitis
0.000V24HCC 35 — Inflammatory Bowel Disease
0.289ESRDHCC 35 — Inflammatory Bowel Disease
0.000RxHCCHCC 67 — Inflammatory Bowel Disease
0.000What This Code Means
Chronic inflammation with ulcers in the rectum and sigmoid colon with an abnormal tunnel-like connection (fistula) formed between the bowel and another structure.
Coding Tips
- •Verify fistula presence and location in documentation
- •Fistulas are a serious complication often requiring surgical intervention
Clinical Significance
Ulcerative rectosigmoiditis with fistula represents an abnormal connection developing from the inflamed rectosigmoid region to adjacent structures. This serious complication typically requires surgical evaluation and may prompt reassessment of whether the diagnosis should be reclassified as Crohn disease, since fistulas are more characteristic of Crohn disease.
Documentation Requirements
- ✓Confirmed ulcerative colitis of the rectum and sigmoid colon
- ✓Documentation of fistula type and location
- ✓Imaging confirmation of fistula tract
- ✓Provider statement attributing fistula to the rectosigmoiditis
- ✓Surgical consultation and management plan
- ✓Consideration of whether diagnosis should be reclassified
Commonly Confused Codes
K51.313 vs K50.113 — K50.113 is Crohn disease of large intestine with fistula; verify underlying diagnosisK51.313 vs K60.3 — K60.3 is anal fistula not related to inflammatory bowel diseaseK51.313 vs K51.013 — K51.013 is pancolitis with fistula; rectosigmoiditis is more limitedK51.313 vs K51.213 — K51.213 is proctitis with fistula; rectosigmoiditis includes sigmoid involvement
Code Hierarchy
└K51Ulcerative colitis└K51.3Ulcerative (chronic) rectosigmoiditis└K51.31Ulcerative (chronic) rectosigmoiditis with complications└K51.313Ulcerative (chronic) rectosigmoiditis with fistula
└K51.313Ulcerative (chronic) rectosigmoiditis with fistula