Flexible sigmoidoscopy is a procedure that enables your physician to examine the lining of the rectum and lower colon (bowel). A soft, flexible tube about the thickness of the index finger is gently inserted into the anus (rectal opening) and advanced or moved into the rectum and the lower part of the colon.
It is most often done as part of a routine screening for cancer for patients over 50 years old.
The rectum and lower colon must be completely emptied of stool (feces) for the procedure to be performed. Your doctor or his/her staff will give you instructions regarding the cleansing routine to be used. If the area to be examined is not totally clear, the doctor will not be able to perform an effective examination. Be sure to follow your doctor's preparation instructions.
Most of your medications can be continued as usual. However, drugs such as aspirin, nonsteroidal anti-inflammatories, and blood thinners are examples of medications whose use should be discussed with your doctor prior to the examination. See preparation instructions.
You will be awake during the procedure. Occasionally, your doctor may give you some light sedation. The procedure is usually well tolerated and rarely causes discomfort. The inside of the colon has few nerve endings; therefore, it is unusual to feel the scope moving within the body.
Air is injected to distend or widen the passage. This may cause a feeling of pressure, gassiness, bloating, or cramping during the procedure. You will lie on your side while the sigmoidoscope is advanced through the rectum and lower colon. The lining of the intestine is examined carefully and biopsies can be taken if necessary.
The procedure usually lasts for five to fifteen minutes. If there is extreme discomfort, you should tell your doctor and the procedure will be terminated.
Your doctor will explain the results to you and discuss any findings. You may have some mild cramping or bloating from the air that was placed into the colon during the examination. This should quickly improve with the passage of gas. You should be able to eat and resume normal activities after leaving the doctor's office.
Flexible sigmoidoscopy and biopsy are safe when performed by physicians with appropriate training and experience in endoscopic procedures. Complications are rare, however, they can occur. They include bleeding from the site of a biopsy or a perforation, which is a tear through the lining of the bowel wall.
It is important to contact your doctor if you notice symptoms of severe abdominal pain, abdominal distension, nausea, fever, chills, or rectal bleeding equal to more than half a cup. Bleeding can occur up to several days after a biopsy.