| K600 | Acute anal fissure |
| K601 | Chronic anal fissure |
| K602 | Anal fissure, unspecified |
| K603 | Anal fistula |
| K6030 | Anal fistula, unspecified |
| K6031 | Anal fistula, simple |
| K60311 | Anal fistula, simple, initial |
| K60312 | Anal fistula, simple, persistent |
| K60313 | Anal fistula, simple, recurrent |
| K60319 | Anal fistula, simple, unspecified |
| K6032 | Anal fistula, complex |
| K60321 | Anal fistula, complex, initial |
| K60322 | Anal fistula, complex, persistent |
| K60323 | Anal fistula, complex, recurrent |
| K60329 | Anal fistula, complex, unspecified |
| K604 | Rectal fistula |
| K6040 | Rectal fistula, unspecified |
| K6041 | Rectal fistula, simple |
| K60411 | Rectal fistula, simple, initial |
| K60412 | Rectal fistula, simple, persistent |
| K60413 | Rectal fistula, simple, recurrent |
| K60419 | Rectal fistula, simple, unspecified |
| K6042 | Rectal fistula, complex |
| K60421 | Rectal fistula, complex, initial |
| K60422 | Rectal fistula, complex, persistent |
| K60423 | Rectal fistula, complex, recurrent |
| K60429 | Rectal fistula, complex, unspecified |
| K605 | Anorectal fistula |
| K6050 | Anorectal fistula, unspecified |
| K6051 | Anorectal fistula, simple |
| K60511 | Anorectal fistula, simple, initial |
| K60512 | Anorectal fistula, simple, persistent |
| K60513 | Anorectal fistula, simple, recurrent |
| K60519 | Anorectal fistula, simple, unspecified |
| K6052 | Anorectal fistula, complex |
| K60521 | Anorectal fistula, complex, initial |
| K60522 | Anorectal fistula, complex, persistent |
| K60523 | Anorectal fistula, complex, recurrent |
| K60529 | Anorectal fistula, complex, unspecified |
| K61 | Abscess of anal and rectal regions |
| K610 | Anal abscess |
| K611 | Rectal abscess |
| K612 | Anorectal abscess |
| K613 | Ischiorectal abscess |
| K6131 | Horseshoe abscess |
| K6139 | Other ischiorectal abscess |
| K614 | Intrasphincteric abscess |
| K615 | Supralevator abscess |
| K62 | Other diseases of anus and rectum |
| K620 | Anal polyp |