A flexible sigmoidoscopy only examines the left side of the colon. Sometimes this is all that is needed when a patient presents with bright red rectal bleeding and no change in bowel habit.
Otherwise a full colonoscopy is usually performed and this examines the entire colon.
All patients having these tests need to take laxatives to cleanse the bowel.
There may be some discomfort during this test. Patients may have entonox if necessary (nitrous oxide and oxygen-commonly used for women in labour). They may have sedation if they feel they need it.
Patients cannot drive or operate machinery 24 hours after sedation.