Which procedure involves the visual examination of the sigmoid colon?

The procedure that involves the visual examination of the sigmoid colon is sigmoidoscopy. This diagnostic method specifically targets the sigmoid colon, which is part of the lower gastrointestinal tract. During sigmoidoscopy, a flexible tube with a camera, called a sigmoidoscope, is inserted into the rectum and advanced through the sigmoid colon. This allows healthcare providers to visualize this section of the colon directly, assess for any abnormalities, take biopsies if necessary, and perform certain therapeutic procedures.

In contrast, endoscopy is a broader term that encompasses visual examinations of various organs using an endoscope, but it does not specify the location, making it less precise in terms of examining just the sigmoid colon. Gastroscopy focuses on the upper gastrointestinal tract, specifically examining the esophagus, stomach, and the first part of the small intestine, and is not related to the sigmoid colon at all. Lastly, proctoscopy is a procedure that examines the rectum and anal canal and does not extend into the sigmoid colon, thus failing to provide the information or assessment needed for the sigmoid region specifically.