Multiple sclerosis (MS) is a chronic condition that can cause various symptoms throughout the body. In some cases, people living with MS may experience problems with their bowels that can result in bowel dysfunction.

MS is a progressive condition that affects the CNS. Evidence indicates that MS is an autoimmune disorder, which means that the immune system mistakenly attacks healthy tissue. With MS, the immune system attacks the protective linings of the nerves, called myelin. The results can disrupt how the brain sends signals to the body.

The course of MS is not predictable, and the condition can affect people in different ways. In some people, nerve damage may affect the function of the bowels. Evidence suggests that more than 50% of people living with MS experience problems with their bladder and bowels, with other sources noting that bowel dysfunction, specifically, affects 39–73% of these individuals.

Treatments are available to help people manage their symptoms, and some home remedies and eating strategies may also help keep bowel movements regular.

In this article, we discuss common bowel problems that may occur in people living with MS. We also look at the treatment options and suggest ways to promote bowel regularity.

A doctor explaining how MS can result in bowel dysfunction.Share on Pinterest
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MS is an autoimmune condition that attacks nerve linings and disrupts the electrical impulses in the body. This disruption can either block or delay nerve signals from the CNS. When MS affects nerve signals that control the bladder and bowel, it can result in dysfunction that causes incontinence or fecal impaction.

As the bladder and bowel dysfunction originates from damage to nerves, some doctors may refer to it as neurogenic bladder and neurogenic bowel dysfunction.

Bowel dysfunction is common in people living with MS. Typically, people will experience the following bowel problems:


Constipation occurs when a person has very few bowel movements or difficulty passing them. It is a common symptom of MS, affecting about 50% of people with this condition. Constipation may occur alone, or it may present alongside other symptoms, including tiredness, stomach pain, and bloating.

Constipation may result directly from MS if nerve damage affects the bowels. However, it can also occur due to issues outside of the condition itself, such as:

  • not getting enough fluid in the diet
  • side effects of medication
  • reduced mobility and physical activity
  • low fiber diet
  • reduced intestinal motility, which is the slower movement of food through the digestive system
  • other issues, such as high stress or anxiety levels

According to the National Multiple Sclerosis Society, constipation may also exacerbate other MS symptoms, such as:

  • pain
  • spasticity
  • bladder dysfunction
  • difficulty with body movements

Fecal impaction

If constipation persists for a prolonged period, it may lead to fecal impaction. In people with this severe bowel condition, very hard stool gets stuck in the rectum or lower colon. This immobile mass of impacted stool will block the passage and cause a buildup of waste, which a person will not be able to pass. If a person does not receive treatment for fecal impaction, it can cause severe damage.

Fecal incontinence

Fecal incontinence occurs when a person cannot control their bowel movements. This lack of control causes stool to leak from the rectum. In people with MS, this may occur if nerve damage affects the bowel or sphincter. However, it may also occur as a result of other issues, such as prolonged constipation.

A 2018 review notes that fecal incontinence affects about 50% of people with MS and is an ongoing symptom in about 25% of cases. Fecal incontinence and constipation also regularly occur together, and a person may experience alternating constipation and incontinence.


Diarrhea occurs when the contents of the bowels move too quickly through the digestive tract and do not give it time to pull enough water from the stool. The result is frequent defecation of loose, watery stools.

Diarrhea may occur due to a loss of sensation in the rectal area, which results in involuntary relaxation, allowing the release of loose stool. MS may also cause overactive bowel functioning or sphincter abnormalities that can lead to diarrhea.

A person with MS who experiences regular bowel dysfunction should see their doctor to check whether it is a sign of MS involvement or another underlying issue.

It may also help to keep a diary of bowel movements, detailing their time and frequency, as well as the consistency of the stool. If a doctor suspects that something from the diet may be causing the symptoms, they might ask the person to note the foods they eat each day in a food journal. This information could help people identify and eliminate problem foods that tend to trigger symptoms.

Once a doctor has diagnosed the cause of bowel dysfunction, they can recommend a treatment plan.

Treatments for bowel dysfunction will vary depending on the underlying cause and severity of symptoms.


Various constipation treatments are available, and doctors may recommend one or more different medicines depending on symptom severity and how well a person responds to treatment. Some examples include:

  • Bisacodyl (Dulcolax): This drug stimulates the bowel muscles to induce bowel movements and may be more suitable as a treatment for occasional constipation.
  • Docusate (Colace): A prescription strength drug for constipation, docusate is a stool softener that helps prevent dry, hard stools.
  • Psyllium husk (Metamucil): Psyllium husk and other fiber supplements absorb extra water, pulling it into the stool, which makes the stool easier to pass.
  • Castor oil: Castor oil is a stimulant laxative, meaning that it causes the bowels to move, squeeze, and contract harder than they usually would, which can help the body pass stubborn stools.

Learn more about natural ways to relieve constipation.

Fecal impaction

If fecal matter becomes impacted and cannot move from the colon or rectum, a person will need treatment to remove the mass of stool. Typically, this involves a procedure called an enema in which a doctor inserts fluid into the rectum that softens the stool and makes it easier to push out. If an enema is ineffective, it may be necessary to break the stool down and remove it by hand.

Fecal incontinence

Doctors may create a specific treatment plan for people with fecal incontinence. Usually, this will involve medications, dietary changes, and bowel training, although surgery may be necessary in some cases.


Treatments for diarrhea include strategies to add bulk to the stool, such as fiber supplements. The medication loperamide (Immodium) may also help relieve diarrhea.

People can take several steps to promote bowel regularity. These include:

  • drinking at least 6–8 glasses of fluids each day
  • getting regular physical activity
  • training the bowels by having set times each day to try emptying the bowels
  • adding more fiber to the diet by eating foods such as fresh fruits, vegetables, and whole grains
  • asking a doctor about over-the-counter or prescription options to help promote bowel regularity, such as stool softeners, bulk-forming supplements, or suppositories
  • using sphincter and pelvic floor exercises to help promote strength in the muscles in the area and avoid incontinence
  • gently massaging the abdomen from left to right in circular motions to stimulate bowel movements

Bowel dysfunction is a common complication in people living with multiple sclerosis. People can implement many strategies to try to manage bowel dysfunction, including lifestyle and dietary adjustments. In some cases, people may require medications or other medical treatments to help relieve symptoms.

A person should work closely with their doctor to identify other possible causes and triggers of bowel dysfunction and create a treatment plan that is effective in helping them manage their symptoms.