Flexible sigmoidoscopy is a procedure similar to colonoscopy in which a doctor examines the inside of the last third of the colon (known as the sigmoid colon) and rectum instead of the full colon.
Flexible sigmoidoscopy is used to:
- detect inflamed tissue, abnormal growths, and ulcers
- look for early signs of cancer
- help doctors diagnose unexplained changes in bowel habits, abdominal pain, bleeding from the anus, and weight loss.
Colonoscopy is the preferred screening method for cancers of the colon and rectum; however, flexible sigmoidoscopy usually requires less preparation time, so some patients choose this option.
How to Prepare for a Flexible Sigmoidoscopy
To prepare for a flexible sigmoidoscopy, one or more enemas are performed about two hours before the procedure to remove all solids from the sigmoid colon. An enema is performed by flushing water, laxative, or sometimes a mild soap solution into the anus using a special wash bottle.
In some cases, the entire gastrointestinal tract must be emptied by following a clear liquid diet for one to three days before the procedure-similar to the preparation for colonoscopy. Patients should not drink beverages containing red or purple dye.
A laxative or an enema may also be required the night before a flexible sigmoidoscopy. A laxative is medicine that loosens stool and increases bowel movements. Laxatives are usually swallowed in pill form or as a powder dissolved in water.