S31.657Open bite of abdominal wall, left flank with penetration into peritoneal cavity

S31.657 is the ICD-10-CM diagnosis code for open bite of abdominal wall, left flank with penetration into peritoneal cavity. It belongs to category S31 (open wound of abdomen, lower back, pelvis and external genitals), block S30-S39 (injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within S31.65 (open bite of abdominal wall with penetration into peritoneal cavity), S31.657 is specifically for open bite of abdominal wall, left flank with penetration into peritoneal cavity. Related codes cover right upper quadrant with penetration into peritoneal cavity (S31.650), left upper quadrant with penetration into peritoneal cavity (S31.651), epigastric region with penetration into peritoneal cavity (S31.652), right lower quadrant with penetration into peritoneal cavity (S31.653), left lower quadrant with penetration into peritoneal cavity (S31.654), periumbilic region with penetration into peritoneal cavity (S31.655), right flank with penetration into peritoneal cavity (S31.656), unspecified quadrant with penetration into peritoneal cavity (S31.659) and 1 more.

Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.

It was added in FY2026, effective October 1, 2025.