Your doctor may use a proctoscope to look inside your rectum. A proctoscope is a narrow, tube-like telescopic camera. Air can be blown through the tube to open up the bowel so it can be seen more clearly. This test can help to rule out problems in your rectum. Alternatively, your doctor may refer you for a flexible sigmoidoscopy or colonoscopy test that will need to be done in hospital. This allows your doctor to look inside your large bowel. These tests are sometimes done to check that your condition isn't caused by something more serious.
Attribution: BUPA