Bowel Problems

Although symptoms of multiple sclerosis (MS) vary significantly between people, bowel problems are common. Bowel issues can be difficult to deal with. In some cases, they are unpredictable or severe. Bowel problems may also be embarrassing or hard to talk about. However, spotting symptoms and seeking support can improve quality of life with MS.1

Understanding MS bowel issues

Our digestive tract is responsible for moving and processing food. The nervous system plays a part in this and connects the gut and the brain. The digestive system starts at the mouth and continues through to the bowel (large intestine) before waste leaves the body.2

Changes in the way the brain and digestive tract talk to one another impact bowel movements. This can lead to constipation, diarrhea, or bowel incontinence. The types of food we eat, how much water we drink, and physical activity also play a role in bowel movements.2

Although usually not dangerous, bowel problems can be difficult to deal with or embarrassing. Dealing with these issues can impact quality of life.

There are several different types of bowel issues that can come with MS, including:3

  • Constipation
  • Incontinence (loss of bowel control)
  • Diarrhea

About half of all people with MS report bowel problems. Constipation is the most common of these symptoms.1,4

Bowel issues, like bladder or sexual issues, often mirror the severity of lower extremity symptoms. For example, a person with severe MS-related symptoms in the lower half of their body is more likely to have bowel problems compared to someone with less severe symptoms.4

However, bowel issues can develop in anyone. They can also be a combination of several changes in the body. It is possible to have bowel issues alongside bladder or sexual issues, too.1,4

Why do bowel problems happen in MS?

There are several reasons why a person with MS might develop bowel problems. The digestive tract and bowel depend on the nervous system. Nerves deliver messages to the bowel that tell the muscles of the bowel to contract. This helps move food and waste through the body. The central nervous system (CNS), including the brain and spinal cord, is also involved in controlling when we go to the bathroom versus when we can wait.2

If nerves are damaged and the gut muscles do not contract well, waste movement slows down. This can lead to constipation. If nerves involved our ability to control when we go to the bathroom are affected, incontinence can develop.2-4

It is also possible for MS drugs to have bowel issues as a side effect. Plus, weakened abdominal muscles from MS can make it difficult to physically have a bowel movement. The same thing happens if abdominal or pelvic muscles are too tight as a result of MS-related spasticity.2-4

In some cases of MS, bladder issues develop. To combat this, some people reduce the amount of water they drink. Not drinking enough water also leads to constipation. Eventually, diarrhea or stool leakage can develop if a person is severely constipated and loose stool finds a way around a blockage.2-4

Plus, some symptoms of MS make it hard to be active. When a person is not as mobile or physically active, constipation can develop. Other common causes of bowel issues can also be at play, like poor diet or irritable bowel syndrome (IBS).2-4

How are bowel problems treated?

Bowel issues are treated based on their type or underlying cause. Constipation is often treated with diet changes, like increased water intake or eating high-fiber foods. It can also be treated with stool bulking agents or laxatives. Drugs that increase intestinal movement may be helpful as well.1,3,5

Diarrhea or incontinence can be treated with drugs or behavioral changes. Avoiding triggers, practicing biofeedback (a mind-body technique), or even surgery may help if symptoms are severe. Treating other underlying medical issues or adjusting drugs that have bowel issues as a side effect are also options.2,5

Even if you do not have bowel issues with MS, there are steps you can take to improve overall bowel function. These include:3,5

  • Drinking plenty of water (6 to 8 glasses a day)
  • Being physically active when possible
  • Eating a varied diet of fruits, vegetables, and high-fiber foods
  • Avoiding constipation-causing foods like processed meats or cheeses
  • Practicing bowel training by setting a regular time to go to the bathroom at least once every 2 to 3 days
  • Talking with your doctor before starting or stopping any drugs, vitamins, or supplements

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Written by: Casey Hribar | Last reviewed: March 2022.