Bowel symptoms can affect nearly 70 percent of individuals with MS. Because MS interrupts or slows the transmission of signals to and from the brain and spinal cord, the electrical impulses to the muscles that are involved in emptying the bowel can become disrupted. MS may also prevent pelvic floor muscles from relaxing. These muscles are used to help void fecal matter. Also, MS may block the natural increase in activity of the colon following meals.
Most individuals experience constipation or slow bowel. Some people with MS have reported bowel incontinence (loss of bowel control) and diarrhea, although these latter symptoms are less common than constipation in individuals with MS.
Constipation is very common among people with MS. In general, inadequate daily fluid, not enough dietary fiber (less than 20 grams of fiber per day), and lack of physical activity all affect the digestive system. Medications and supplements may also contribute to constipation.
Constipation is characterized by infrequent bowel movements (usually fewer than three bowel movements per week), or by needing to strain to eliminate stool. Constipation can contribute to abdominal cramping, bloating, fullness, or discomfort.
A very distressing symptom, bowel incontinence is the loss of voluntary bowel control. This can range from occasionally leaking a small amount of stool and passing gas to completely losing control of bowels. Bowel retraining can help encourage normal bowel movements. Aspects of this routine may include setting aside time every day to try to empty the bowels, taking in enough daily fiber to keep stool formed, and avoiding foods that trigger a loose stool.
Some individuals experience diarrhea. Diarrhea occurs when the bowel contents progress too rapidly along the digestive tract, resulting in frequent bowel movements that yield watery, loose stools. This is sometimes the result of allergies or sensitivity to spicy foods or dairy products, contaminated water or food, a change in activity level, or a stomach virus. Chronic diarrhea can also contribute to dehydration or poor nutrient absorption in people with MS.