Gastrointestinal Issues

Difficulty swallowing, feelings of nausea or bloating, constipation, and difficulty eliminating are all common symptoms of PD.

Scientists point to two explanations for these difficulties.The same brain changes in PD that cause stiffness and slow movement also affect the muscles involved in swallowing and in pushing food through the digestive system. In addition, Parkinson’s can affect the nerves that line the digestive tract, called the enteric nervous system. In particular, researchers have found Lewy bodies in neurons lining the intestines of people with Parkinson’s. This has led to the suggestion that cell damage in the gut may signal the beginning of PD, and that cell death in the brain is a relatively late stage of disease.

Difficulty Swallowing 

People with Parkinson’s tend to swallow less often and less completely, and as a result some 70 percent have too much saliva, which often pools in their mouth. Sucking on hard candy, preferably sugarless, can stimulate swallowing and provide temporary relief from drooling. An effective treatment, available by prescription, is atropine eye drops taken on or under the tongue. Adjusting anti-Parkinson’s medications may also make it easier to swallow. In addition, medical conditions unrelated to Parkinson’s can lead to difficulty swallowing. Your doctor may image your mouth and throat using a modified barium swallow test  to diagnose swallowing difficulties.


Nausea or bloating can result when the stomach empties its contents into the small intestine too slowly, a condition called gastroparesis. It can cause particular problems for people taking levodopa (Sinemet) if the drug remains in the stomach too long and cannot be absorbed by the small intestine and travel to the brain. There is no therapy for gastroparesis; however, different ways of delivering levodopa are being studied, such as skin patches, that would avoid this problem.


Constipation, defined as fewer than three bowel movements per week, is perhaps the most widely recognized gastrointestinal symptom of Parkinson’s disease. Studies have shown that this symptom often begins before motor symptoms are diagnosed. In one study, researchers found that having a bowel movement less often than once a day indicated a risk of developing Parkinson’s four times higher than average. 

In some people with Parkinson’s disease, constipation may occur due to the improper functioning of the autonomic nervous system. The autonomic nervous system is responsible for regulating smooth muscle activity.  If this system is not working properly, the intestinal tract may operate slowly, causing constipation.  Medications used to treat Parkinson’s disease including levodopa, dopamineagonists, amantadine and especially the anticholinergics Artane and Cogentin can also cause constipation.  Other causes for constipation include:

  • Not drinking enough water
  • A diet low in fiber
  • Lack of exercise
  • Travel or other change in routine
  • Eating large amounts of dairy products
  • Stress
  • Resisting the urge to have a bowel movement
  • Antacid medicines containing calcium or aluminum
  • Other medications (especially strong pain medicines such as opioids, antidepressants, and iron pills)
  • Medical problems such as irritable bowel syndrome (IBS), diabetes, and colorectal cancer
  • Pregnancy

Things you can do to avoid constipation:

  • Eat a well-balanced diet with plenty of fiber.  Good sources of fiber are fruits, vegetables, legumes, bran, and whole grain bread. Breads are considered to be whole grain if they contain at least 3 grams of fiber per serving as shown on the nutritional content label.  Most of the fiber in fruits is found in the skins and fruits with edible seeds such as strawberries have the most fiber.
  • Drink 48-64 ounces of water and other fluids each day.  Milk can cause constipation in some people.
  • Exercise daily.
  • Try drinking warm liquids, especially in the morning. Consider warming your prune juice instead of drinking it cold.
  • Add fruits and vegetables to your diet.
  • Eat prunes and/or bran cereal.
  • If needed, use a very mild stool softener or laxative (such as Peri-colace or Milk of Magnesia).  Do not use laxatives for more than two weeks without calling your doctor since laxative overuse can worsen your symptoms.

Difficulty emptying the bowel is another common symptom of PD. There is no specific treatment, but avoiding constipation and keeping the stool soft should help.

Bladder Problems 

People with Parkinson’s may also have bladder problems. The most common difficulty is a frequent and urgent need to urinate, even when the bladder is not full. If this is occuring, then after determining that this problem is not due to a bladder or urinary infection or other more immediate medical issue, a variety of medications can be prescribed to help this problem, including oxybutynin, tolterodine, solifenacin, and darifenacin. Incontinence tends to be a fairly uncommon symptom in PD.