Up to 70 percent of people living with multiple sclerosis (MS) experience bowel problems. Constipation — or difficulty passing stool — is the most common. Others may experience incontinence (loss of bowel control) or diarrhea. These symptoms can stem from MS itself or from related factors, like medications or reduced mobility.

A MyMSTeam member said it feels like their days “revolve around the bathroom.” Another noted that bowel issues limit their quality of life.

Here’s how to get a better handle on bowel problems with MS and improve daily comfort.

What Causes Bowel Problems in MS?

MS is a chronic autoimmune disease in which the body’s defense system mistakenly attacks the central nervous system. This leads to inflammation and damage to myelin, the protective coating around nerves.

MS can disrupt nerve signals between the brain and bowels, leading to a condition called neurogenic bowel dysfunction. Studies show that between 39 percent and 73 percent of people with MS have this condition.

MS can also make it harder for the muscles of the pelvic floor to relax. These muscles play a key role in eliminating waste from the body.

Additionally, MS may block the gastrocolic reflex, a natural reflex that helps move food through the lower digestive tract after eating.

Constipation

Constipation is the most common bowel problem in people living with MS. It occurs when stool moves too slowly through the intestines. As a result, the body absorbs too much water from the waste, making it hard, dry, and difficult to pass.

Constipation is the most common bowel problem in MS.

MS can lead to constipation in several ways. A low-fiber diet, lack of fluids, or limited physical activity can all contribute. Some MS medications — including opioid pain relievers — may also cause or worsen constipation. When opioids are the cause, it’s called opioid-induced constipation.

Many people with MS experience gait problems (trouble walking) and fatigue (extreme tiredness that doesn’t go away with rest). These symptoms can slow digestion and reduce muscle movement in the intestines, making it harder to pass stool. Weak abdominal muscles may also make bowel movements more difficult.

Spasticity — muscle spasms or stiffness — is another common symptom of MS. If the pelvic floor muscles spasm or tighten, it can be hard to relax them during a bowel movement.

Bladder problems, such as incontinence or a spastic (overactive) bladder, may cause some people to reduce how much fluid they drink. This can further contribute to constipation.

Diarrhea

Diarrhea means having soft, loose, or watery stools. It can occur when bowel contents move too quickly through the digestive system, leaving little time for water to be absorbed.

In some people, MS may cause the bowel to become overactive, which can lead to diarrhea. However, diarrhea isn’t always caused by MS. It may also be triggered by a food allergy, food intolerance, a stomach virus, or shifts in activity levels.

Bowel Incontinence

Bowel incontinence refers to a loss of voluntary control of the bowels. It’s usually linked to diarrhea in people with MS, although it may also be caused by long-term constipation.

People with MS can experience both constipation and incontinence or bowel leakage. Some people may alternate between the two symptoms.

One MyMSTeam member said that they are usually constipated as a result of their pain medication, but when they have an attack, they “don’t have full control.”

MyMSTeam Members’ Experiences With Bowel Problems

Most people experience occasional bowel problems. They may have a day or two of constipation or diarrhea based on what they ate. But for people with MS, these symptoms can be more frequent. They can be frustrating or embarrassing, and they can even affect a person’s quality of life.

Many MyMSTeam members have shared their difficulties with bowel issues. One member described their bowel issues as “constant,” writing that experiencing bowel problems for eight weeks was causing them to feel extra fatigued.

Another member found that especially tough days triggered their incontinence: “I am finding that on my bad days when I have really bad exhaustion, my bowels ‘leak.’ Sometimes, it is so bad that I bleed.”

“I am finding that on my bad days when I have really bad exhaustion, my bowels 'leak.' Sometimes, it is so bad that I bleed.”

— A MyMSTeam member

It’s normal to be frustrated by these symptoms. Some members discuss how unfair it feels: “I shouldn’t be incontinent at 32,” wrote one member experiencing frequent bowel problems. Another responded that at 52, they are “still too young.”

How To Manage Bowel Problems With MS

Fortunately, bowel problems are manageable with the help of your healthcare team. Your neurologist may refer you to a specialist, such as a gastroenterologist.

Lifestyle changes, over-the-counter (OTC) drugs, and prescription medications can help get bowel problems under control.

Lifestyle Changes

Changing your lifestyle habits can promote regular bowel movements. Here’s how.

Drink Plenty of Fluids

According to the National Multiple Sclerosis Society, you should aim to drink at least 48 ounces (six to eight glasses) of water each day. As one MyMSTeam member recommended, “Drink at least a liter of water a day. … The water helps keep things moving.”

According to the National Multiple Sclerosis Society, you should aim to drink at least 48 ounces (six to eight glasses) of water each day.

Talk to your doctor if you’re worried about leaks from drinking more water.

Eat Enough Fiber

Fiber, which helps add bulk and soften the stool, can be found in fresh fruits and vegetables, as well as in whole-grain breads and cereals.

One MyMSTeam member shared that they get additional fiber by adding two to three spoonfuls of flaxseed and chia seeds to their yogurt.

Another wrote that adding fiber to their diet helped ease their bowel symptoms more than medication: “I had gotten a prescription from my doctor, which didn’t help. What has helped is eating more fruits and vegetables and once a day, drinking a glass of juice with Miralax in it.”

You should talk to your doctor before making any major changes to your diet. Generally, it’s a good idea to incorporate high-fiber foods into your diet only gradually to help prevent gas, diarrhea, or bloating.

Get Physical Activity

Doctors used to advise against exercise for people with MS. Today, health experts understand that exercise can have tremendous wellness benefits for people with MS. Aside from its positive impacts on physical and mental health, exercise helps keep stool moving regularly through the digestive tract.

Managing Constipation

In addition to adding fiber to your diet and drinking plenty of fluids, using certain OTC medications and treatments may help ease constipation. Taking these medications around the same time each day may help promote regular bowel movements.

• Stool softeners — Docusate, found in medications such as Colace and Surfak, helps soften the stool, making it easier to pass. Mineral oil can also help ease constipation by lubricating the digestive tract, but it shouldn’t be taken at the same time as a stool softener.
• Osmotic laxatives — Sorbitol solution, magnesium hydroxide (such as Phillips Milk of Magnesia), and polyethylene glycol (like Miralax) are types of osmotic laxatives. An osmotic laxative is a type of medication that helps relieve constipation by drawing water into the intestines, softening stools, and making them easier to pass.
• Stimulant laxatives — Also known as chemical irritants, these medications stimulate the movement of stool through the bowel. Senna (sold under brand names like Ex-Lax) is an example of a stimulant laxative.
• Glycerin suppositories — Suppositories are inserted via the rectum and may be recommended if oral laxatives don’t provide relief. These suppositories are taken 15 to 30 minutes before attempting a bowel movement.
• Bisacodyl suppositories — These suppositories (such as Dulcolax) stimulate strong movements in the rectal muscles. They’re a generally safe and useful option for constipation when used as advised.
• Enemas — Enemas work by injecting liquid directly into the rectum. Mini-enemas may be used regularly as long as your doctor says it’s OK.

There are medication options for constipation in addition to those on this list. Always talk to your doctor before starting any new medication, even if it doesn’t require a prescription.

If your MS medications are causing constipation, talk to your doctor so they can adjust your treatment plan. “I had this problem, and it turned out to be the meds that caused it,” wrote a MyMSTeam member.

Managing Diarrhea

Several strategies can help manage diarrhea in people living with MS. These include medications, dietary changes, exercises, and support devices.

Bulk Formers

Bulk-forming products, such as wheat dextrin and psyllium, add moisture and volume to the stool. This can help regulate bowel movements and make stools easier to pass.

It's important to drink plenty of water when using bulk-forming agents to prevent them from causing blockages or worsening constipation.

Antidiarrheals

If bulk formers aren’t effective, your doctor may prescribe antidiarrheal medications. Diphenoxylate combined with atropine slows movement of the intestines and is typically used for short-term use.

Loperamide (such as Imodium A-D) is an over-the-counter option that works similarly and usually causes fewer side effects.

Other Diarrhea Treatment Options

Some people find relief with pelvic floor exercises or physical therapy, which may help improve control over bowel movements.

In certain cases, mechanical options — such as soft anal plugs — can help manage leakage by providing a temporary seal. These options may be useful during travel or social events.

Join the Conversation

On MyMSTeam, people share their experiences with MS, get advice, and find support from others who understand.

What are your tips for managing constipation? Let others know in the comments below.