This condition is characterized by a weak or interrupted urinary stream. Initiation of urination is difficult or slow, and the finish is just the same. Difficulty urinating must be distinguished from dysuria (page 144), which is painful urination, and anuria or oliguria (page 51), which is absent or reduced volume of urine. The pathophysiological cause of difficulty urinating is obstruction. If we then visualize the urinary tree from the prepuce on up to the bladder, we can visualize the causes of obstruction at each level. These are illustrated in the figure given for Dysuria.
· Prepuce—Phimosis and paraphimosis
· Meatus—Meatal stricture
· Urethral—Urethral stricture, urethral calculus
· Prostate—Prostatitis, prostatic hypertrophy, prostatic carcinoma, prostatic calculus
· Bladder—Bladder neck obstruction due to stricture, median bar hypertrophy, calculus or neoplasm
· Extrinsic lesions of the bladder or urethra—Uterine fibroids, pregnant retroverted uterus, or carcinoma of the vagina
· Lesions of the innervation of the bladder wall—This may be due to lower motor neuron disorders such as poliomyelitis, cauda equina tumors, or disks; tabes dorsalis; or diabetic neuropathy. It may also be due to upper motor neuron lesions such as multiple sclerosis, transverse myelitis, or spinal cord tumor.
Approach to the Diagnosis
The first thing to do is to established that there is an obstruction to the flow of urine. This may now be done with ultrasonography, but catheterization may still be done in the acute situation. The history will be helpful in many cases. Difficulty voiding in a young person will most likely point to a urethral stricture or prostatitis from previous gonorrhea or urethral injury, whereas difficulty voiding in an older man would suggest prostatic hypertrophy. A history of hematuria would suggest the possibility of a vesicle or urethral calculus. Ask if the patient is on any drugs or has a history of diabetes. An abnormal neurological examination might point to diabetic neuropathy, multiple sclerosis, or spinal cord tumor.
The laboratory workup should include the CBC, urinalysis, chemistry panel, VDRL, and a urine culture and sensitivity. If these tests are negative, a urologist needs to be consulted for cystoscopy and cystometric testing.
Other Useful Tests
1. Anaerobic cultures
2. Prostate-specific antigen (PSA) titer
3. Intravenous pyelogram (IVP) and voiding cystogram
4. Gynecology consult
5. Neurology consult
6. Electromyography (EMG) and nerve conduction velocity testing
7. Plain films of the thoracolumbar spine
8. MRI of the thoracic or lumbar spine
9. Laparoscopy