What is neurogenic bowel?

Neurogenic bowel is the loss of normal bowel function caused by a nerve problem. Many different and unrelated conditions can cause neurogenic bowel disorder. A spinal cord injury or a nerve disease like Parkinson disease, multiple sclerosis, or diabetes may damage the nerves that help control the lower part of your colon.  This is the part of the body that sends solid waste out of the body. This condition gets in the way of your normal ability to store and get rid of stool waste. It often causes constipation and stool leakage or accidents.

The food you eat goes to your GI (gastrointestinal) tract for digestion. You might think of your GI tract as a long tube. Here is how it works:

• Muscles around the GI tract push the food by contracting and squeezing the tube in a wave-like pattern (peristalsis). 

• Starting at the mouth, food goes down the food pipe (esophagus) to the stomach.

• It then goes into the intestines or bowel. The first part of the intestines is called the small intestine. It absorbs the nutrients. The food your body can’t use then goes on into the large intestine (colon).

• Your colon reabsorbs excess water from the undigested food (called stool). The stool is stored in the last part of the GI tract called the rectum.

• Over time, your body removes the stool through the anus during a bowel movement (BM). A ring of sphincter muscles keeps the stool inside the rectum until you have a BM.

The muscles and nerves around your rectum and anus need to work together for your bowels to work correctly. Nerves control the muscles of the rectum. They signal when the rectum is full. Damage to these nerves can interfere with bowel control. The damage may reduce the peristalsis in the muscles around the colon. The damage may block signals to or from the rectum and anus. This means you may not feel when you need to have a BM. Or you may not be able to have a BM when you want.

There are 2 main kinds of neurogenic bowel, depending on where in its course the nerves are damaged:

• Reflex (spastic) bowel problem. This is when you can’t voluntarily relax the anal sphincter. You usually have constipation. Signals between the colon and the brain become disrupted. In reflex bowel problems, the reflex that triggers a BM still works. But you may not feel it coming. An unplanned BM can happen when the rectum is full. This pattern of neurogenic bowel is seen when the nerve injury is in the brain or the spinal cord. A reflex bowel problem is also known as an upper motor neuron injury.

• Flaccid bowel problem. This is reduced movement in the colon. There is less peristalsis, and the sphincter is looser than normal. This can lead to constipation with frequent leaking of stool. A flaccid bowel problem may follow a lower spinal cord injury.

Neurogenic bowel can lead to BM accidents (incontinence), constipation, and other problems like infection. These problems can cause physical, social, and emotional difficulties. People with neurogenic bowel may be able to set up a bowel management program that helps to reduce problems.

What causes neurogenic bowel?

Nerve damage may lead to neurogenic bowel. This can happen from:

• Injury, such as spinal cord injury

• Nervous system disease, such as multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS)

• Stroke

• Parkinson disease

• Diabetes with nerve damage

What are the symptoms of neurogenic bowel?

Neurogenic bowel causes a loss of normal bowel function. Damaged nerves disrupt your rectum's ability to store and get rid of waste. Because of disrupted signals between the colon and the brain, you may not feel the urge to have a BM. This often causes constipation and BM accidents. Reflex bowel problems may cause a sudden, unplanned BM when the rectum is full. Flaccid bowel problems may lead to frequent leakage of stool because the sphincter does not close tightly. Neurogenic bowel may cause:

• Constipation or diarrhea

• Trouble having a BM

• Loss of feeling that the bowel is full

• Upset stomach (nausea) or crampy abdominal pain

• Stool leakage or frequent BM accidents

How is neurogenic bowel diagnosed?

Healthcare providers will ask about your health history, recent symptoms, past health conditions, and family health history. The provider may ask how often you have BM accidents or constipation. You may need to fill out a stool diary to record when you have BMs. Providers generally do a physical exam, including a rectal exam and testing of your reflexes. You may need other tests, such as:

• Anorectal manometry to measure sphincter strength

• Electromyography to test the electrical activity of the muscles around the anus and rectum

• MRI or CT scan of your brain or spinal cord

• Ultrasound imaging of the anus

You will usually get the diagnosis from a neurologist or gastroenterologist.

How is neurogenic bowel treated?

People with neurogenic bowel need to have a routine bowel management program. This includes scheduled routines to remove the stool from the rectum on a regular basis. This helps prevent accidents, constipation, infections, and bowel blockage. A bowel program also includes diet changes, medicines, and other methods. Your healthcare team can help you create a bowel management program. Your bowel care may include:

• Belly (abdominal) muscle training

• Botulinum toxin to help decrease anal sphincter spasticity

• Colostomy surgery to make an opening for stool to empty through instead of the rectum

• Dietary changes

• Electrical (neural) stimulation of the belly muscles

• Exercise and activity plans

• Laxative regimen (may include both pills taken by mouth and suppositories)

• Pulsed water irrigation

• Scheduled bowel routine to physically remove the stool from your rectum

• Surgery to create a hole (stoma) through which you can flush water into the top of your bowel

• Using a finger to trigger the sphincter muscle (digital rectal stimulation)

By following a bowel management program, you may need less help from others. It may also help prevent complications, such as hemorrhoids or bowel blockage. Good bowel care practice helps prevent BM accidents. It also helps to prevent hemorrhoids, serious constipation, and intestinal blockage. You can work with your healthcare team to create and maintain the best bowel care program for your situation.

If you need a caregiver, they will need training in good bowel care. You should be included in this training if possible. The goal is to give you the most freedom and flexibility. It will help limit the impact of bowel dysfunction on your quality of life.

Key points about neurogenic bowel

• Neurogenic bowel is the loss of normal bowel function due to a nerve problem. It causes constipation and stool leakage or incontinence.

• Nerve damage may be due to a brain or spinal injury or a health condition, such as multiple sclerosis.

• Symptoms include trouble having a bowel movement, belly pain, leaking stool, and frequent bowel movement accidents.

• Tests for diagnosis may include an MRI or CT scan of your brain or spinal cord and an ultrasound of the anus.

• Treatment includes creating a bowel management program. This includes scheduled times to remove stool from the rectum.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your healthcare provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your healthcare provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions.