A sigmoidoscopy (sometimes called a flexible sigmoidoscopy) is a test that looks at the inside of the rectum and the part of the colon closest to the rectum (the sigmoid colon). You can usually have it as an outpatient.
A sigmoidoscope is a tube with a light and camera on the end. You lie curled on your left side and a doctor or nurse passes the tube into your back passage. A small amount of air is pumped into the bowel to make it easier to see inside it. This will make you feel like you need the toilet, but the feeling will gradually go away once the test is over.
During the test, the doctor or nurse will take samples of tissue (biopsies) from any areas of the colon that look abnormal. This is painless.
You should be able to go home as soon as the test is over.