What can sigmoidoscopy be used to view?

Sigmoidoscopy is a medical procedure that allows for direct visualization of the sigmoid colon and the rectum. This procedure uses a flexible tube with a light and camera, known as a sigmoidoscope, to examine these specific areas of the lower digestive tract. As a result, it is particularly effective for diagnosing conditions such as tumors, polyps, and inflammation located within the lower colon.

The correct answer highlights that sigmoidoscopy can be used to view a tumor in the lower colon, which is well within the scope of what this procedure is designed to assess. Conditions such as tumors are often detected through the inspection of the mucosa in the sigmoid colon, making this screening a crucial tool in colorectal health.

In contrast, the other options refer to other parts of the digestive system or conditions that are not within the reach of a sigmoidoscopy. Duodenal ulcers, for example, occur in the upper part of the small intestine and would require a different form of examination like an upper endoscopy. Conditions related to the ileocecal valve pertain to the junction between the small and large intestine, which is also beyond the viewing area of a sigmoidoscope. Gastric ulcers exist within the stomach, again out of the