Constipation & Nausea

Constipation & Nausea

Difficulty swallowing, feelings of nausea and constipation are all common symptoms of Parkinson’s disease (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.

Additionally, 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 PD. This suggests cell damage in the gut may signal the beginning of PD and cell death in the brain is a relatively late stage of disease.


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

In some people with PD, constipation may occur due to the improper functioning of the autonomic nervous system, which is responsible for regulating smooth muscle activity of the gut. If this system is not working properly, the intestinal tract may slow down, causing constipation. Medications for PD, including levodopa and dopamine agonists, as well as the anticholinergics amantadine and trihexyphenidyl (Artane), also cause constipation. Other causes include:

  • Not drinking enough water
  • A diet low in fiber
  • Lack of exercise
  • 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

How to avoid constipation:

There is no specific treatment, but avoiding constipation and keeping the stool soft should help.

  • Eat a well-balanced diet with plenty of fiber. Good sources of fiber include fruits, vegetables, legumes, bran, and whole grain bread.
  • Drink 48 to 64 ounces of water each day. 
  • Exercise daily.
  • Drink 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. Do not use laxatives for more than two weeks without notifying your doctor.


Nausea or bloating can result when the stomach empties its contents into the small intestine too slowly, a condition called gastroparesis. For people taking levodopa (Sinemet), this is a problem because the drug 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, to avoid this problem.

Page reviewed by Dr. Chauncey Spears, Movement Disorders Fellow at the University of Florida, a Parkinson’s Foundation Center of Excellence.


Sign Up for Our E-Newsletter

Get the latest news about PD research, resources and community initiatives – straight to your inbox.

Please enter a valid email

Skip step

Invalid year format. Eg: 2020
Skip step
Zip code is required for chapter communications
Skip step

*Please note that not all content is available in both languages. If you are interested in receiving Spanish communications, we recommend selecting “both" to stay best informed on the Foundation's work and the latest in PD news.

Skip step

Thanks for Signing Up

We are proud to have you as a part of our community. To ensure you receive the latest Parkinson’s news, research updates and more, please check your email for a message from us. If you do not see our email, it may be in your spam folder. Just mark as “not spam” and you should receive our emails as expected.

mail icon

Subscribe here to get the latest news on treatments, research and other updates.