Bowel and Bladder Problems

Reviewed by: HU Medical Review Board | Last reviewed: September 2021

Neuromyelitis optica spectrum disorder (NMO) can affect the nerves of the spinal cord, which can lead to issues with bladder and bowel functions. If you experience this, know you are not alone. Bowel and bladder accidents can be embarrassing and impact your social and emotional life, leaving you feeling isolated.1

You have options, and it is not your fault. Bowel and bladder problems that occur as a result of NMO can be challenging, but with planning and some modifications, you can live an active, productive, and social life.1

What causes bladder and bowel problems with NMO?

Nerve fibers in your brain, spinal cord, and eye have a protective coating called myelin. When this coating is damaged, it is called demyelination. NMO, among other diseases, is a demyelinating disease because it attacks the myelin coating on nerve fibers.2,3

When myelin is damaged, nerve signals can slow or stop. In the spinal cord, damaged myelin leads to a condition called transverse myelitis.2,3

What is transverse myelitis?

Transverse myelitis occurs when inflammation damages the spinal cord. You may sometimes hear transverse myelitis referred to as “spinal cord lesions.” Transverse myelitis can cause muscle weakness, paralysis, or pain. It may also lead to bladder and bowel problems.4,5

Bladder and bowel symptoms of transverse myelitis include:4,5

  • Constipation
  • Bowel incontinence (unintentional passage of stool, rarer than constipation)
  • Frequent need to urinate
  • Difficulty holding urine
  • Urine leakage (incontinence)

These bladder and bowel symptoms are known as neurogenic bladder and bowel.1

Neurogenic bladder

Your urinary system is a complex network of nerves and muscles that work together with your brain and spinal cord. Under normal conditions, the brain, bladder, and spinal cord coordinate the holding and voluntary release of urine. NMO, transverse myelitis, and other demyelinating diseases may damage the network of nerves that communicate signals from the brain and spine to the bladder, causing neurogenic bladder. This can lead to dysfunction in the following ways:1,4

  • Overactive bladder is what it is called when the bladder squeezes before it is really full. This leads to frequent urination. Over time, it can lead to urinary incontinence.
  • Underactive bladder is what it is called when the bladder will not release urine when full. Over time, this can lead to infection or kidney damage.

Neurogenic bowel

Like your bladder, your bowels work together with the muscles and nerves around your rectum and anus. Damage to these nerves can interfere with bowel control.1,5

Normally, your brain provides signals to your digestive tract to keep your bowels properly moving. This process is part of digestion and is not voluntary – that means your body does it automatically without you thinking about it. When nerves are damaged in diseases like NMO, it can block these normal signals. This leads to decreased movement of your gut and impaired movement of your bowels. This can cause constipation because your intestines are not properly moving material.

Nerve damage can also change or decrease the normal sensation you have that it is time to have a bowel movement. This nerve damage can make it hard to control the sphincters (muscles in the digestive tract) that allow you to have voluntary bowel movements. This may lead to involuntary bowel movements, or bowel incontinence.

Nerve damage can decrease the involuntary movements of your digestive tract around the colon. You may not be able to feel when you need to have bowel movements.1,5


There are steps you can take to help better control your bladder and bowel. Your first step is to develop a bladder and bowel plan. This plan should include 3 important steps:1

Optimizing diet and fluid intake

Fluid intake should be spread out throughout an entire day. Try not to drink large amounts of fluid at once.1

Preventing urinary incontinence

There are many products available to avoid bowel and bladder accidents. Medicines that relax the bladder can help decrease urinary frequency. Talk to your doctor about which type is best for you. Intermittent catheterization can also help. In this procedure, a small tube called a catheter is inserted into the bladder. It empties urine and is removed when finished. This is done about every 4 hours.1

Preventing constipation

Fiber or a fiber supplement can be a good source to help achieve proper stool consistency. Exercise and an active lifestyle can help with moving your bowels. Abdominal massage may also help to move the bowels.

Your doctor may recommend other treatment, such as:1

  • Laxatives
  • Suppositories or enemas
  • Manual removal of stool


Proper hygiene can help reduce the risk of infection if you frequently lose control of your bladder or bowels.1

Partnering with your doctor, listening to your body, and following your bladder and bowel plan will help you carry out your daily routines without bowel and bladder problems standing in your way.

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