What procedure allows examining the rectum and lower part of the colon?

The procedure that allows for the examination of the rectum and the lower part of the colon is known as proctoscopy. This method involves the use of a proctoscope, which is a specialized instrument designed to visualize the inside of the rectum and the sigmoid colon. It is particularly useful for diagnosing conditions such as hemorrhoids, rectal bleeding, or tumors in that region.

Proctoscopy is a more targeted procedure compared to other options, focusing specifically on the lower gastrointestinal tract. In contrast, colonoscopy examines a larger section, including the entire colon, and is not limited to the rectum. The barium swallow is an imaging test for the upper digestive tract, and a nuclear medicine study involves the use of radioactive materials to observe organ function, which does not pertain to direct examination of the rectal area.