What is neurogenic bowel?

Neurogenic bowel is the loss of normal bowel function. It’s caused by a nerve problem. A spinal cord injury or a nerve disease 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 problem gets in the way your normal ability to store and eliminate waste. It often causes constipation and bowel accidents.

The food you eat goes to your gastrointestinal tract (GI tract) for digestion. You might think of your GI tract as a long tube. Muscles around the GI tract push the food by contracting and squeezing the tube in a wave-like pattern. This is called peristalsis. Starting at the mouth, food travels down the esophagus to the stomach, and then into the intestines or bowel. The first part of the intestines absorbs the nutrients. The food your body can’t use then travels onward into the large intestine (colon). Your colon reabsorbs excess water from the undigested food which is called stool. The stool is stored in the last part of the GI tract called the rectum. Eventually, your body expels 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 properly. Nerves control the muscles of the rectum, and 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 two main kinds of neurogenic bowel, depending on the nerves affected.

  • Reflex (spastic) bowel problem. This is when you can’t voluntarily relax the anal sphincter. You may 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. A reflex bowel problem may follow an upper central nervous system 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 complications. 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
  • Neurologic disease, such as multiple sclerosis or amyotrophic lateral sclerosis
  • Stroke

What are the symptoms of neurogenic bowel?

Neurogenic bowel causes a loss of normal bowel function. Damaged nerves disrupt the ability of your rectum 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 leaks of stool because the sphincter does not close as tightly. Neurogenic bowel may cause:

  • Constipation or diarrhea
  • Difficulty having a BM
  • Loss of sensation that the bowel is full
  • Nausea or abdominal pain
  • Stool leaking or frequent BM accidents

How is neurogenic bowel diagnosed?

Doctors will ask about your medical history, recent symptoms, past medical conditions, and family medical history. The doctor 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. Doctors 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 and/or spinal cord
  • Ultrasound imaging of the anus

You may get the diagnosis from a gastroenterologist or other specialist.

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, and bowel blockage. A bowel program also includes diet changes, medicines, and other methods. Your medical team can help you develop a bowel management program. Your bowel care may include:

  • Abdominal muscle training
  • Botulinum toxin to help decrease anal sphincter spasticity
  • Colostomy surgery to create an opening for stool to empty through instead of the rectum
  • Dietary changes
  • Electrical (neural) stimulation of the abdominal muscles
  • Exercise and activity plans
  • Laxative regimen (may include both oral pills 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. You may also avoid related problems, such as hemorrhoids or bowel blockage. Good bowel care practice helps avoid BM accidents. It also helps to prevent hemorrhoids, serious constipation, and intestinal blockage. You can work with your medical team to create and maintain the best bowel care program for your situation.

Key points

  • Neurogenic bowel is the loss of normal bowel function due to a nerve problem. The muscles and nerves around your rectum and anus need to work together for your bowels to work properly. Damage to these nerves can cause lack of bowel control, leading to constipation and bowel accidents.
  • Neurogenic bowel can be either a “reflex” or “flaccid” type. In the reflex type, you can’t voluntarily relax the anal sphincter. But an unplanned BM can happen reflexively when the rectum fills. In a flaccid bowel, there is less movement of the colon and the sphincter may be loose.
  • Both types of neurogenic bowel can cause constipation and accidents.
  • A bowel management program includes scheduled times to remove the stool from the rectum on a routine basis. This helps maintain bowel health and prevent accidents and complications.
  • You can work with your healthcare team to develop a bowel care program that creates the best outcome for you.

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.