Which of the following procedures carries a risk of rectal perforation?

The procedure that carries a risk of rectal perforation is flexible sigmoidoscopy. During a flexible sigmoidoscopy, a physician inserts a flexible tube into the rectum to examine the lower part of the colon. The manipulation required to navigate the sigmoid colon can sometimes lead to perforation, especially if there is underlying pathology such as diverticulosis, inflammation, or tumors that weaken the colonic wall. While rectal perforation is a rare complication, it is an important risk that practitioners must be mindful of during this procedure.

In contrast, colonoscopy, which involves examining the entire colon, also poses a risk of perforation but primarily emphasizes the entire gastrointestinal tract, and these risks relate more widely to the entire scope of the procedure rather than being exclusive to the rectal area. Endoscopic ultrasound focuses on imaging and sampling of gastrointestinal structures rather than performing an invasive procedure through the colon itself, and as such, the perforation risk associated with it is significantly lower. Esophagogastroduodenoscopy addresses the upper gastrointestinal tract, making rectal perforation irrelevant in that context. Thus, the specific context of flexible sigmoidoscopy, especially its focus and anatomy involved in the procedure, solidifies its association with rectal perforation