Which surgical procedure is a 75-year-old male likely to undergo after being admitted with an acute sigmoid obstruction due to perforated diverticulitis?

The most appropriate surgical procedure for a 75-year-old male who is admitted with an acute sigmoid obstruction due to perforated diverticulitis is a colostomy with Hartmann's pouch. This approach is often utilized in cases of diverticulitis, especially when there is perforation and potential contamination of the peritoneal cavity.

Hartmann's procedure involves the resection of the affected segment of the colon and the creation of a colostomy. The distal portion of the bowel is usually left in place but not connected to the rectum; instead, it is closed off. This is beneficial because it allows for immediate diversion of bowel contents, effectively managing the acute condition and preventing complications related to fecal contamination.

Additionally, Hartmann's pouch provides a potential for future restoration of bowel continuity once the inflammation has resolved, which is a significant consideration in the management of diverticulitis. This option aligns with the need for urgent intervention in the case of perforation while also considering the possibility of reestablishing normal bowel function later.

The other options may not be as appropriate given the specific circumstances of acute sigmoid obstruction and perforation.