Bladder and Bowel Problems in Multiple Sclerosis

Last updated Jan. 12, 2022, by Marisa Wexler, MS

✅ Fact-checked by Inês Martins, PhD


Multiple sclerosis (MS) is an autoimmune disease that causes damage to the brain and other parts of the nervous system. This damage can interfere with the brain’s ability to regulate bodily functions, which may result in bladder and bowel complications. While these problems can be distressing and embarrassing for patients, they can usually be managed with appropriate care and precautionary steps.

Bladder problems in MS

The bladder is an elastic sac that holds urine. Normally, when a person urinates, muscles around the bladder constrict to push liquid out, and sphincters open to let the urine exit the body. These processes are regulated by signals from the nervous system, which may be impaired in MS. As a consequence, the bladder may be spastic (overactive) and unable to hold the normal amount of urine, or it may not empty fully during urination.

At least 4 out of 5 MS patients experience some form of bladder dysfunction. Common symptoms of this dysfunction include needing to urinate very frequently or urgently, waking up multiple times at night to urinate, hesitancy in starting urination, or incontinence (the inability to hold in urine).

Depending on the specific symptoms experienced by the individual, medications and other treatments — such as physical therapy to strengthen the muscles of the pelvic floor — can help to manage MS-related bladder problems. Lifestyle and habit changes, such as modifications in diet or fluid intake, may also help.

Bowel problems in MS

The bowel is the final portion of the digestive tract that holds stool before elimination. As MS can cause damage to parts of the nervous system that regulate bladder function, it can also impair bowel function.

Bowel problems affect more than 2 out of 3 people with MS. The most common bowel-related problem reported in MS is constipation, or infrequent bowel movements (usually less than three per week), and/or a lot of difficulty in defecating.

When constipation is severe, stool can build up in the bowels, which also puts pressure on the bladder and aggravates urinary problems, as well as worsens spasticity. In addition, patients often reduce fluid intake as a means to control their bladder problems, which can make stools harder and worsen constipation.

Less commonly, people with MS experience diarrhea or incontinence, a reduced ability to control bowel movements voluntarily. Impaction, a hard mass of stool in the rectum that cannot be eliminated, can occur in MS and contribute to incontinence. It usually requires medical attention to resolve.

Factors such as diet and physical activity have a sizable effect on bowel health, so a healthy diet with appropriate exercise is often recommended to help manage bowel issues. Medications for specific symptoms may also be used (e.g., stool softeners or laxatives to ease constipation).


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