K57.21 Diverticulitis of large intestine with perforation and abscess with bleeding

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from K57 Diverticular disease of intestine

Excludes1 (never code together)

• congenital diverticulum of intestine (Q43.8)
• Meckel's diverticulum (Q43.0)

Excludes2 (not included here)

• diverticulum of appendix (K38.2)

Code also

• if applicable peritonitis K65.-

Applies from K57.2 Diverticulitis of large intestine with perforation and abscess

Excludes1 (never code together)

• diverticulitis of both small and large intestine with perforation and abscess (K57.4-)

MS-DRG index

Defines the logic of DRG(s) 377-379 in MDC 06.

Approximate ICD-9-CM (GEMs)

• 562.13 Diverticulitis of colon with hemorrhage (approximate)
• 569.5 Abscess of intestine (approximate)

Code annotations containing back-references to K57.21

Back-references to K57.2

• Type 1 Excludes: K63.0 Abscess of intestine ("abscess of intestine with diverticular disease (K57.0, K57.2, K57.4, K57.8)")
• Type 1 Excludes: K63.1 Perforation of intestine (nontraumatic) ("perforation (nontraumatic) of intestine with diverticular disease (K57.0, K57.2, K57.4, K57.8)")

Back-references to K57

• Code Also: K65 Peritonitis ("if applicable diverticular disease of intestine (K57.-)")
• Type 1 Excludes: K92.2 Gastrointestinal hemorrhage, unspecified ("diverticular disease with hemorrhage (K57.-)")

Diagnosis Index entries for K57.21

• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › with › diverticular disease (intestine) › large intestine › with › bleeding
• Diverticulitis (acute) › intestine › large › with › abscess, perforation › with bleeding
• Perforation, perforated (nontraumatic) (of) › diverticulum (intestine) › large intestine › with › bleeding
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion) › with or following › diverticular disease (intestine) › large intestine › with › bleeding
• Rupture, ruptured › diverticulum (intestine) › large intestine › with › bleeding

Nearby codes

• K57.11 Diverticulosis of small intestine without perforation or abscess with bleeding
• K57.12 Diverticulitis of small intestine without perforation or abscess without bleeding
• K57.13 Diverticulitis of small intestine without perforation or abscess with bleeding
• K57.2 Diverticulitis of large intestine with perforation and abscess
• K57.20 Diverticulitis of large intestine with perforation and abscess without bleeding
• K57.21 Diverticulitis of large intestine with perforation and abscess with bleeding (this code)
• K57.3 Diverticular disease of large intestine without perforation or abscess
• K57.30 Diverticulosis of large intestine without perforation or abscess without bleeding
• K57.31 Diverticulosis of large intestine without perforation or abscess with bleeding
• K57.32 Diverticulitis of large intestine without perforation or abscess without bleeding
• K57.33 Diverticulitis of large intestine without perforation or abscess with bleeding