Bladder Outlet Obstruction

If you have pain in your abdomen, pain when you pee and/or an inability to empty your bladder, you might have a bladder outlet obstruction (BOO). An obstruction means that something is blocking your pee at the neck of your bladder, right before it goes into your urethra. There are many possible causes, from scar tissue to prostate cancer. Treatments are available.


What’s bladder outlet obstruction (BOO)?

Bladder outlet obstruction (BOO) is when the neck at the very bottom of your bladder gets blocked. The neck is where your bladder connects to your urethra, which carries urine (pee) out of your body. A blockage stops or slows down the flow of pee. Possible blockages include scar tissue, bladder stones, a large gland, cancer or a tumor.


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What’s bladder outlet obstruction in utero?

Bladder outlet obstruction in utero is also called fetal bladder outlet obstruction or fetal lower urinary tract obstruction (LUTO). This rare condition is where a developing baby’s pee is blocked, which reduces the amount of amniotic fluid, increases the size of their bladder and can cause many other problems.

Who is most likely to have a bladder outlet obstruction?

BOO is most common in those over age 65 and people designated male at birth (DMAB) and is often linked to prostate problems. More men than women get it. Women and people designated female at birth (DFAB) with cystocele (prolapsed bladder) are more likely to have a bladder outlet obstruction than other women. Children and babies, including developing fetuses, can also get BOO.


How common is bladder outlet obstruction (BOO)?

BOO is considered common. Men ages 50 to 60 have an 80% chance of having some degree of bladder outlet obstruction.

How does the bladder normally work?

Your bladder is an organ that sits between your hip bones. It’s located above your urethra, below your kidneys. Urine from your kidneys drains down into your bladder, which can stretch to hold about 1.5 to 2 cups of pee.


Does a bladder outlet obstruction (BOO) hurt?

Pain can be a symptom of BOO. You may feel pain in your lower abdomen, and/or pain when you pee.

Is a bladder outlet obstruction a sign of cancer?

There could be many possible reasons for BOO, including prostate cancer.

Symptoms and Causes

What causes a bladder outlet obstruction (BOO)?

The causes of bladder outlet obstruction include:

  • Scar tissue in your urethra.
  • Bladder stones.
  • Tumors in your rectum.
  • Procedures for stress urinary incontinence (SUI) surgery.
  • Non-cancerous (benign) lesions or cysts.
  • Urethra, vaginal or cervical cancer.
  • Urethral scarring (stricture) disease.
  • Tumors in your uterus or cervix.
  • Bladder or uterus falling down into your vaginal area (pelvic organ prolapse).
  • An enlarged prostate gland (benign prostatic hyperplasic, or BPH) or prostate cancer.
  • Severe constipation or impaction of stool.

Bladder outlet obstruction sometimes causes lower urinary tract symptoms (LUTS).

What are the symptoms of bladder outlet obstruction (BOO)?

You may have BOO if you:

  • Have trouble starting your urine stream.
  • Feel like you have a full bladder but can’t empty it completely.
  • Pass pee frequently during sleeping hours.
  • Have pain in your lower abdomen.
  • Have a pee flow that starts and stops or is very slow.
  • Void often, but very little pee comes out.
  • Feel pain when passing pee.

Diagnosis and Tests

How is a bladder outlet obstruction (BOO) evaluated and diagnosed?

Tests may include:

  • Blood tests to check for kidney damage.
  • Urine cultures to test for infection.
  • Ultrasound of your kidneys and bladder to find where the pee blockage is occurring.
  • Urine testing to look for blood in your pee.
  • A scope to look for narrowing of your urethra.
  • Urodynamic evaluation (a test to show how the muscles of your bladder and sphincters function).
  • Ultrasound (an image of bladder and kidneys to check for retention of urine).

What questions might a healthcare provider ask to diagnose a bladder outlet obstruction?

  • Do you feel pain in your abdomen, or pain when you pee?
  • When you go to pee, does it take a while to start?
  • Do you ever pee in your sleep?
  • When you’re done peeing, do you feel like your bladder is still full, or partially full?
  • When you pee, does your urine stream start and stop (out of your control)?

Management and Treatment

How is a bladder outlet obstruction (BOO) treated?

The type of treatment depends on what’s obstructing your bladder. For example, bladder stones are treated differently than prostate cancer.

Some BOO blockages can be treated by:

  • Inserting a thin, flexible tube called a catheter through your urethra and into your bladder.
  • Inserting a catheter into your bladder through an incision in your lower abdomen.
  • Medications.
  • Surgical procedures to remove the obstruction.

It’s important to get treatment as soon as possible. If you don’t, there could be complications.


How can I prevent a bladder outlet obstruction?

If the condition that blocks your bladder neck is preventable, then the bladder outlet obstruction might be preventable, too.

What medications can I take to reduce my risk of a bladder outlet obstruction?

Talk to your healthcare provider about medications that could reduce your risk of the different conditions that cause an obstruction.

What kind of healthcare provider treats BOO?

A urologist, who specializes in the genitourinary tract can help with your kidneys, bladder, adrenal glands, urethra, male fertility and reproductive organs. A gynecologist can help people designated female at birth with issues of pelvic organ prolapse.

Outlook / Prognosis

What are the long-term complications of a bladder outlet obstruction?

Complications can happen if you don’t have your bladder outlet obstruction diagnosed and treated quickly. Complications include:

  • Kidney problems.
  • Bladder problems.

How long will I have a bladder outlet obstruction?

Your BOO-related symptoms should resolve with treatment. But bladder outlet obstruction can come back. In some cases, you may require surgery.

Living With

When can I go back to work/school?

Unless the pain is unbearable, bladder outlet obstruction shouldn’t keep you from your normal daily activities.

When should I go to the emergency department?

Go to the emergency department if the pain is unbearable. This could be a sign of complications.

What questions should I ask my healthcare provider about BOO?

  • What’s the cause of my bladder outlet obstruction?
  • What’s the best treatment option for me?

A note from Cleveland Clinic

If you have symptoms of a bladder outlet obstruction, don’t hesitate to see your healthcare provider. Pay attention to your pee. Is your urine stream normal? Or does very little pee come out, despite your fluid intake? Are you peeing slower than normal? Or do you have trouble starting to pee, no matter how hard you try? Are you in pain? All of these are reasons to get checked out by your healthcare provider to avoid kidney and bladder complications.

Medically Reviewed

Last reviewed on 02/09/2022.

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