Implementation
The rectal examination can be performed in three different body positions of the patient. In most cases, the patient lies on the examination table on his left side with his legs slightly drawn up, with his buttocks as close as possible to the edge of the table. Other possible positions are the knee-elbow position on the examination couch or standing up (this position is, however, often perceived as very uncomfortable) or the lithotomy position on the gynecological examination chair, where the doctor can simultaneously palpate the abdomen with the left hand.
After putting on gloves, the doctor first inspects the perineal region. During this inspection, he looks for redness, tears or signs of infection of the anal mucosa and hemorrhoids (about 70% of the over-30s suffer from these, although most of them are symptom-free). Next, the doctor inserts the finger smeared with Vaseline into the anus, paying attention to the tone, i.e. the muscle strength of the sphincter muscles.
If the pressure of the finger on the rectum hurts, this may indicate an inflammatory process in the area of the appendix (see: appendicitis) or – in women – in the ovaries, the fallopian tubes or the space between the uterus and the rectum (Douglas space). The doctor can palpate the man’s prostate at a depth of about 7-8 cm. By palpation, he can assess the size, consistency, shifting of the mucous membrane and the ability to separate it from the surrounding tissue.
The size of a chestnut, the consistency of a tense ball of the thumb and an easily palpable furrow in the middle would correspond to normal findings. If the prostate is painful under pressure, this indicates acute or chronic inflammation. After the examination, the doctor will look for remains of stool, mucus, blood or pus on the fingerstall.
Based on the coloration of the blood or stool, he can distinguish gastrointestinal bleeding from hemorrhoidal bleeding, because if there is bleeding in the stomach or intestinal tract, the blood is already black or colors the stool dark when it is excreted. Hemorrhoidal bleeding is indicated by fresh, light-colored blood. Stool residues can still be used for a haemoccult test, which is used to diagnose colon cancer.Finally, the patient is offered wipes to clean the vaseline.
The digital rectal examination allows both benign and malignant changes in the prostate to be detected by an uncomplicated and quick examination. The same applies to colon carcinomas, 20-30% of which develop in the area accessible with the palpating finger. The examination bears no risks for the patient.
In order to detect the above-mentioned changes in the prostate gland at the earliest possible stage, when the prognosis is significantly better with treatment than in later stages, it is recommended that men from the age of 45 years should be examined regularly once a year. Men who, for example, have an increased risk of developing prostate cancer due to family history of prostate cancer, can be examined from the age of 40. The sensitivity of DRU – i.e. the probability that a patient will actually be diagnosed as sick by the examination – is about 60%.
The specificity – the probability that healthy people will also be recognized as healthy by the test – is about 75%. The test is therefore not absolutely reliable. There are controversial opinions about the benefit of the test.
The significance of the test is limited, because it can only detect superficial tumors of a certain size on the side facing the intestine. Furthermore, the result is highly dependent on the examiner. Therefore, the rectal examination as the only early detection examination is rather insufficient.
A further examination option is the determination of the PSA level in the blood. The prostate-specific antigen is an enzyme that is produced in the prostate and which may be elevated in the presence of a carcinoma, which is why the value is used as a tumor marker. However, PSA determination is primarily used to monitor the course of existing prostate carcinoma.
48 hours before the test, the patient should avoid pressure on the prostate through cycling, horseback riding, competitive sports, sexual intercourse, as well as aspirin or other blood-thinning medications in order not to influence the value. The PSA level may also be elevated in cases of inflammation of the prostate or benign prostate adenomas. Values above 4 ng/ml should be clarified.
Another examination of the prostate is the transrectal ultrasound examination. Here the ultrasound probe is inserted rectally, which allows suspicious areas of the prostate to be visualized. The statutory screening program for men over 45 years of age provides for an annual examination of the prostate by means of a rectal examination and of the genitals by palpation of the testicles and the lymph nodes in the groin.
However, the PSA determination is not included. This test is controversial because it is not clear whether men really live better or longer by regularly determining their PSA level. If the rectal examination indicates changes in the prostate, further more specific examinations may follow, such as a tissue sampling (prostate biopsy), a colonoscopy or the PSA determination, which would now also be covered by health insurance because of suspected changes in the tissue. Tissue removal is the only way to reliably detect or rule out a carcinoma. In this procedure, several tissue samples are taken with a fine needle ultrasound-guided through the rectum and then examined under the microscope for cancer cells.
