A flexible sigmoidoscopy is similar to a colonoscopy in that a flexible scope is passes from your anus to visualize your colon.
Unlike a colonoscopy, a sigmoidoscopy is only meant to visualize the lower colon up until the splenic flexure.
This is a great test to evaluate diseases of the lower colon such as rectal bleeding or lower left sided abdominal pain.
Furthermore, the preparation is much simpler and sedation is rarely required.
It usually takes less than 5 minutes to complete the exam.