ICD-10-CM > N00-N99 > N80-N98 > N80 > N80.5 > N80.51 N80.51 Endometriosis of the rectum Non-Billable/Non-Specific Codes N80.511Superficial endometriosis of the rectumN80.512Deep endometriosis of the rectumN80.519Endometriosis of the rectum, unspecified depth