K51.31

Ulcerative (chronic) rectosigmoiditis with complications

Header / non-billable

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This code does not map to a risk-adjusting HCC in the loaded models.

Coding notes

Excludes 1 never coded together · Excludes 2 may co-exist

Inherited from K51Ulcerative colitis

Excludes 1

Crohn's disease [regional enteritis] (K50.-)

Use additional

code to identify any associated fistulas, if applicable: anal fistula (K60.3-) anorectal fistula (K60.5-) rectal fistula (K60.4-) code to identify manifestations, such as: pyoderma gangrenosum (L88)

Inherited from K50-K52Noninfective enteritis and colitis

Includes

noninfective inflammatory bowel disease

Excludes 1

irritable bowel syndrome (K58.-) megacolon (K59.3-)

Inherited from chapter 11Diseases of the digestive system

Excludes 2

certain conditions originating in the perinatal period (P04-P96) certain infectious and parasitic diseases (A00-B99) complications of pregnancy, childbirth and the puerperium (O00-O9A) congenital malformations, deformations and chromosomal abnormalities (Q00-Q99) endocrine, nutritional and metabolic diseases (E00-E88) injury, poisoning and certain other consequences of external causes (S00-T88) neoplasms (C00-D49) symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Official Guidelines for K51.31

FY 2026 ›

I.C.11Chapter-specific guidanceChapter 11: Diseases of the Digestive System (K00-K95)