Sigmoidoscopy is the visual examination of the inside of the rectum and sigmoid colon, using a lighted, flexible tube connected to an eyepiece or video screen for viewing. This device is called an endoscope. The colon (large intestine) is 5 to 6 feet long. During a sigmoidoscopv, only the last 1 to 2 feet of the colon is examined. This last part of the colon, just above the rectum, is called the sigmoid colon.
Reasons For The Exam
Sigmoidoscopy is performed to diagnose the cause of certain symptoms. It is also used as a preventative measure to detect problems at an early stage, even before the patient recognizes symptoms. The following are some reasons for performing a sigmoidoscopy.
- Bleeding—Rectal bleeding is very common. It often is caused by hemorrhoids or by a small tear at the anus, called a fissure. However, more serious problems can cause bleeding. Benign polyps can bleed. It is important to identify and remove polyps at an early stage before they can become cancerous. Rectal and colon cancers bleed and require immediate diagnosis and treatment. Finally, various forms of colitis and inflammation can cause bleeding.
- Diarrhea—Persistent diarrhea should always be evaluated. There are manv causes of diarrhea and the exam is of great help in tracking down the specific cause.
- Pain—Hemorrhoids and fissures are some causes of pain around the anus or in the rectum. Discomfort in the lower abdomen can be caused by tumors. Diverticulosis can occur in the lower bowel. With this condition, small pockets or sacks project from the bowel.
- X-ray Findings—A barium enema x-ray exam may show abnormalities that need to be confirmed or treated by sigmoidoscopy.
- Detection—Colon cancer is one of the most common cancers in the country. It is highly curable if it is found early. This cancer usually begins in the colon as a polyp that remains benign for many years. Therefore, it is generally advisable to have a sigmoidoscopy after age 40 or 50. If parents, brothers, or sisters have had colon polyps or colon cancer, it is even more critical to have this exam. The tendency to develop colon cancer and polyps can be inherited.