Constipation is a common symptom of Parkinson's that can cause discomfort and impact the benefit of Parkinson's medications. Current medical therapies are limited, but researchers are urgently working toward treatments for constipation in Parkinson's.
Constipation occurs when bowel movements, or "stools," become less frequent or more difficult to pass. Some define constipation as less than three bowel movements per week, but what constitutes constipation can vary because our usual bathroom patterns differ. Some people go every day, while others may go only three or four times per week.
Constipation can significantly impact quality of life, causing bloating, discomfort and nausea. It is one of the most persistent symptoms of Parkinson's disease (PD), arising often years before the motor symptoms and affecting people throughout their disease course. Constipation also can slow absorption and lower the effectiveness of Parkinson's medications, such as levodopa. For these reasons, it is a major priority for Parkinson's researchers.
In Parkinson's, constipation can be part of the disease process. PD can affect the autonomic nervous system, a network of nerves that directs bodily functions we don't consciously control, such as blood pressure and digestion. When digestive tract movement slows in PD, constipation can happen. Recent research also has linked changes in gut bacteria (the microbiome) with Parkinson's disease; these disruptions may contribute to constipation.
Constipation also can be a side effect of some Parkinson's drugs. It's a common problem, for example, with Artane (trihexyphenidyl), which sometimes is used to ease tremor.
Other prescription and over-the-counter medications, including narcotic painkillers, antacids that contain calcium (Tums) or aluminum (Mylanta), or iron supplements, can contribute to constipation, too. Too little physical activity, water or fiber also can play a role.
The first steps in treating constipation are diet and lifestyle adjustments:
- Drink at least six 8-ounce glasses of water per day.
Water increases flow through the digestive tract. You may need more water, especially in hot weather, but start with at least six full glasses per day. Keep in mind that caffeine and alcohol can cause dehydration, which will worsen constipation. And consider drinking warm liquid in the mornings, as this sometimes can stimulate a bowel movement.
- Add more fiber to your diet.
Fiber helps drive waste through the intestine. Gradually increase the amount of fiber in your diet with vegetables, berries, fruits with skin (such as pears and apples) and whole grains.
- Eat smaller meals throughout the day.
Some people notice more small meals rather than fewer larger meals helps with constipation as it allows more time for digestion.
- Exercise regularly.
Abdominal muscle movement helps activate the digestive system. Steady, moderately strenuous exercise, such as walking, swimming or light weightlifting, may help ease constipation.
When diet and exercise are not enough, your doctor may recommend over-the-counter or prescription medications, including stool softeners, laxatives or enemas.
- Stool softeners, such as Colace (docusate), can be used if stools are hard. These can be taken on a daily basis for short periods.
- Laxatives work in different ways. Some, such as Miralax (polyethylene glycol), pull water into the colon to ease constipation. These are fairly gentle and very popular. "Stimulant" laxatives, such as Dulcolax (bisacodyl) or Senokot (senna), promote muscle contractions in the digestive tract. These are not recommended for daily use as they can be more harsh on the system.
- Enemas are sometimes used for significant constipation, but these should be used cautiously and only under the advice of your health care provider.
Today, there are no prescription drugs specifically for Parkinson's constipation. However, the U.S. Food and Drug Administration (FDA) has approved drugs for "chronic idiopathic constipation" — constipation due to an unknown medical cause or medication. These drugs — Linzess (linaclotide), Amitiza (lubiprostone) and Trulance (plecanatide) — may be considered after diet changes, exercise and the above over-the-counter therapies have failed.
As with all Parkinson's symptoms, discuss the treatment of constipation with your doctor and work together to find a regimen that fits your needs.
Given constipation's significant impact on quality of life, The Michael J. Fox Foundation (MJFF) emphasizes research into understanding and treating constipation:
- Testing new therapies: Several therapies are currently in human trials. MJFF is funding studies to test a novel drug for Parkinson's constipation as well as a fiber supplement that acts as a fertilizer for "good" gut bacteria. Other ongoing work is testing probiotics and a gentle hands-on treatment to ease constipation. Sign up for MJFF's study-matching tool Fox Trial Finder to learn more about ongoing trials.
- Understanding experience of Parkinson's: To better understand the occurrence and impact of Parkinson's symptoms, including constipation, MJFF is gathering data from people with Parkinson's and people without (control volunteers) through its online clinical study Fox Insight. Register today to contribute valuable information through questionnaires and surveys on your medical history.
- Developing tests for Parkinson's: Researchers are working toward a better understanding of the role of the gut in Parkinson's. The MJFF-sponsored Systemic Synuclein Sampling Study (S4) measures the Parkinson's protein alpha-synuclein in colon tissue (and other tissues and fluids). In a partnership between MJFF and consumer genetics company 23andMe, investigators are analyzing gut bacteria (the microbiome) to see if and how this differs in Parkinson's compared to people without the disease and among people with PD who have different symptoms (tremor vs. walking problems, for example). Another project from MJFF grantees at Emory University is measuring gut inflammation through a person's breath. These projects may help develop tests to diagnose and track PD and assess new therapies.