Physicians may have to examine the rectum and anus for a range of reasons. Officially called a digital rectal examination (DRE), this test can give a cursory indication of whether certain medical problems might need a closer look with a light and camera. The exam involves the insertion of a gloved index finger into the rectum for about a minute, during which the patient can be in one of several positions. A rectal examination helps to inspect the tissue and identify any potential growths or areas of inflammation.
A rectal examination can be performed in a few positions. For a woman, it may be performed in conjunction with a broader gynecological exam, with the patient lying on her back and her legs spread and attached to stirrups. Otherwise, a doctor may just ask a patient to lean over the side of the examining table. Another common position is with the patient lying on his side and pulling his top leg to the chest.
A range of symptoms could lead a doctor to perform a rectal examination — or none at all. During a prostate gland, uterus or ovarian cancer screening, the rectum offers the best angle for doctors to identify growths and other abnormalities. When patients complain of symptoms like excessive pain, digestive disorders, or rectal bleeding, however, doctors may perform a quick digital test to feel whether the source of the problem lies with hemorrhoids or polyps in the rectum near the anus. Often, this examination will involve tissue palpation and a check for tumors on major organs.
If the cause of pain or bleeding is not identified during a rectal examination, doctors may use more exacting equipment to identify the culprit. A sigmoidoscopy may be performed to inspect the lower part of the large intestine, or rectum, with a lighted camera and remove most growths that are found. Colonoscopies can be used to inspect and clear the entire large intestine, or colon. Once removed, any suspect tumors, polyps or other growths are routinely screened for malignancy.
These latter two tests require advance preparation, primarily a one- to three-day liquid diet to clear a path for the equipment and best reveal abnormal tissue. A rectal examination, however, requires no advance preparation. The American Society of Clinical Oncology recommends that patients tell doctors about any inflammation ahead of time, so he or she can best avoid tender areas. Nevertheless, some discomfort is to be expected.
