This is, to all intents & purposes, a high anterior resection without an anastomosis. Instead the rectal stump is over sewn & the proximal end of bowel is brought out as an end colostomy in the left iliac fossa.

It is performed when an anastomosis is deemed unsafe for reasons of sepsis (perforated diverticulitis), poor bowel viability or preparation, or to expedite surgery in a critically ill or frail patient.