Bladder outlet obstruction
BOO; Lower urinary tract obstruction; Prostatism; Urinary retention - BOOBladder outlet obstruction (BOO) is a blockage at the base of the bladder. It reduces or stops the flow of urine into the urethra. The urethra is the tube that carries urine out of the body.
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Causes
This condition is common in aging men. It is often caused by enlarged prostate. Bladder stones and bladder cancer are also more commonly seen in men than women. As a man ages, the chances of getting these diseases increase greatly.
Other common causes of BOO include:
- Pelvic tumors (cervix, prostate, uterus, rectum)
- Narrowing of the tube that carries urine out of the body from the bladder (urethra), due to scar tissue or certain birth defects
Less common causes include:
- Cystocele (when the bladder falls into the vagina)
- Foreign objects
- Urethral or pelvic muscle spasms
- Inguinal (groin) hernia
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Symptoms
The symptoms of BOO may vary, but can include:
- Abdominal pain
- Continuous feeling of a full bladder
- Frequent urination
- Pain during urination (dysuria)
- Problems starting urination (urinary hesitancy)
- Slow, uneven urine flow, at times being unable to urinate
- Straining to urinate
- Urinary tract infection
- Waking up at night to urinate (nocturia)
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Exams and Tests
Your health care provider will ask about your symptoms and medical history. You will undergo a physical exam.
One or more of the following problems may be found:
- Abdominal swelling
- Cystocele (women)
- Enlarged bladder
- Enlarged prostate (men)
Tests may include:
- Blood chemistries to look for signs of kidney damage
- Cystoscopy and retrograde urethrogram (x-ray) to look for narrowing of the urethra
- Tests to determine how fast urine flows out of the body (uroflowmetry)
- Tests to see how much the urine flow is blocked and how well the bladder contracts (urodynamic testing)
- Ultrasound to locate the blockage of urine and find out how well the bladder empties
- Urinalysis to look for blood or signs of infection in the urine
- Urine culture to check for an infection
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Treatment
Treatment of BOO depends on its cause. A tube, called a catheter, is inserted into the bladder through the urethra. This is done to relieve the blockage.
Sometimes, a catheter is placed through the belly area into the bladder to drain the bladder. This is called a suprapubic tube.
Most often, you will need surgery for long-term cure of BOO. However, many of the diseases that cause this problem can be treated with medicines. Talk to your provider about possible treatments.
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Outlook (Prognosis)
Most causes of BOO can be cured if diagnosed early. However, if the diagnosis or treatment is delayed, this can cause permanent damage to the bladder or kidneys.
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When to Contact a Medical Professional
Contact your provider if you have symptoms of BOO.
References
Andersson KE, Wein AJ. Pharmacologic management of lower urinary tract storage and emptying failure. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 120.
Berney D. Urinary and male genital tracts. In: Cross SS, ed. Underwood's Pathology. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 20.
Boone TB, Stewart JN, Martinez LM. Additional therapies for storage and emptying failure. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 127.
Capogrosso P, Salonia A, Montorsi F. Evaluation and nonsurgical management of benign prostatic hyperplasia. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 145.