The test provides a direct view of the bowels. It makes it possible to perform a biopsy without surgery. It can be readily performed in a doctor's office without major preparation. It's somewhat invasive, although less so than EGD, ERCP, or colonoscopy. Improvements in viewing instruments have made this test much more comfortable for patients.
Most doctors use a soft, flexible tube that is less than half an inch in diameter.
Rigid sigmoidoscopy is mainly used to examine hemorrhoids and abnormalities in the anus. If you are extremely anxious about this procedure, discuss it with your doctor ahead of time. You can be given a sedative, but you will have to arrange to have someone drive you home afterward. Published under license from Houghton Mifflin Company. All rights reserved.