What instrument is used to examine the sigmoid colon?

The instrument specifically designed to examine the sigmoid colon is the sigmoidoscope. This device is a flexible tube with a light and camera that allows healthcare providers to visually inspect the lower part of the colon, which includes the sigmoid colon.

Unlike the colonoscope, which is used to examine the entire colon, the sigmoidoscope is tailored for examinations limited to the rectum and sigmoid colon, typically allowing for a quicker and less invasive procedure. The endoscope is a broader term that refers to any instrument used to examine the interior of a hollow organ, while the gastroscope is specifically intended for examining the stomach. Therefore, the correct instrument for examining the sigmoid colon, as indicated, is the sigmoidoscope.