The sigmoid is the last 10 to 15 inches of the colon, which descend down the left side of the body, connecting the large intestine to the rectum. If bleeding or other discomfort occurs in this area of the colon, it could signal a serious condition that requires an internal examination.
A sigmoidoscopy (also called a flexible sigmoidoscopy) is a procedure that enables the gastroenterologist to examine this part of the colon. It involves inserting a sigmoidoscope – a thin, flexible tube equipped with a lighted camera – into the anus, through the rectum, and up into the sigmoid. The instrument can also inflate the sigmoid with air, to improve visibility.
As the instrument passes through, the camera transmits images of the intestinal lining for the gastroenterologist to examine.
The patient, who lies on the left side during the procedure, may feel pressure, bloating, or cramping, but it should not be painful. The procedure usually takes 10 to 20 minutes.
The patient’s rectum and lower colon must be completely empty for this procedure. The doctor will provide specific instructions on the cleansing routine, which may include enemas and/or laxatives and diet restrictions. This procedure usually does not require sedation, so the patient can drive home.