Sigmoidoscopy is an endoscopic procedure in which the doctor looks inside the large intestine with the help of a flexible tube with a light on the end. A rigid sigmoidoscope is not commonly used these days because the flexible tube is more comfortable for the patient and is easier to use for the physician. It also allows a longer segment of the large intestine to be examined.
When is it used?
Sigmoidoscopy is a diagnostic as well as a screening procedure. It is used in asymptomatic cases as a screening test for cancer of the large intestine. It is also used to assess a variety of disorders such as bleeding from the rectum, intractable or chronic diarrhoea, pain in the lower abdomen, and inflammation of the mucosal lining of the rectum.
How should one prepare for sigmoidoscopy?
Follow the doctor's instructions. The doctor usually orders a low residue diet beginning one day prior to the test. An enema is given about an hour before the procedure. The enema contains a laxative and is introduced into the rectum to facilitate bowel movement. The inside of the intestine can be better viewed if it is clean and empty. Some patients may be given an antibiotic before the procedure.
What happens during the procedure?
The procedure does not require anaesthesia. The patient is asked to lie down on their left side with the knees bent and pulled up towards the abdomen. The tip of the sigmoidoscope is lubricated to lessen any discomfort. The inside of the large intestine can be viewed on a TV monitor and can be recorded on a video tape. A sample of tissue known as a biopsy may be taken for laboratory testing. Air is introduced into the intestines in order to view the intestines better.
What happens after the procedure?
No special measures are taken after the procedure, unless the doctor gives special orders. The patient can be sent home immediately in most cases.
What are the risks associated with this procedure?
The risks include damage to the lining of the intestine from the endoscope, bleeding and infection. Mild pain and a bloating sensation may be felt over the lower abdomen. This is due to the air that is introduced into the rectum during the test and disappears quickly after the extra air is passed out from the body.