This procedure lets your physician look at the large intestine from the rectum through the last part of the colon called the sigmoid or descending colon. Physicians may use this exam to find the cause of diarrhea, abdominal pain or constipation. With this exam, the doctor can see bleeding, inflammation, growths or polyps, and ulcers. The sigmoidoscopy cannot detect polyps or cancer in the transverse or ascending colon and is not considered a substitute for a colonoscopy.
The colon and rectum must be empty for flexible sigmoidoscopy to be thorough and safe. Your doctor may tell you to have only clear liquids for 12-24 hours before your exam. Instructions for how to prepare your colon will be given by the doctor's office and may include a bowel cleansing preparation or enema or both.
Do not eat or drink for 6 hours before the procedure. Before coming to the hospital's endoscopy suite, please remove all jewelry. You may wear dentures or hearing aids during the exam.
You will lie on your left side for this exam. The doctor inserts a thin, flexible, lighted tube (an endoscope) into the rectum and slowly guides it through your descending or sigmoid colon. The scope uses a tiny TV lens to send a magnified picture to a TV screen. The scope also blows air into the colon, which inflates it for better viewing by your doctor. During the exam, polyps may be removed from the colon and tissue samples (biopsies) taken. These will be sent to the laboratory for further testing.
During the procedure, you may feel gas-like cramping in the lower abdomen. This is relieved when the air escapes from the colon or is removed through the endoscope. The exam takes 10-20 minutes. Complications of the exam are uncommon but may include bleeding and perforation (puncture) of the colon.