Man with stomach or gastrointestinal pain

Man with stomach pain (© Syda Productions -

SCOTTSDALE, Ariz. — Constipation and irritable bowel syndrome (IBS) could be early warning signs of Parkinson’s disease, a new study explains. A team from the Mayo Clinic Arizona found that constipation displayed a link to more than double the risk of developing this neurological condition within the five years leading up to its diagnosis. Moreover, IBS shows an association with a 17-percent heightened risk.

There has been much speculation that gastrointestinal symptoms could be precursors to events like strokes or brain aneurysms. Similarly, some theories suggest that certain gut conditions might also herald the onset of neurological diseases, including Parkinson’s.

To investigate this, scientists analyzed data from a nationwide U.S. medical record network. They examined 24,624 individuals diagnosed with Parkinson’s disease of unknown origin and compared them with those diagnosed with Alzheimer’s disease, cerebrovascular disease, or neither. The individuals with Parkinson’s were matched with peers from the other groups based on age, sex, race, ethnicity, and the duration of diagnosis. The aim was to contrast the prevalence of various gut conditions recorded in their electronic health records for an average period of six years before their Parkinson’s diagnosis.

In a different approach to the same hypothesis, the research team classified adults diagnosed with any of 18 gastrointestinal conditions into separate groups. These individuals were then paired with those not having the specific gastrointestinal condition. Their medical records were monitored for five years to observe the onset of Parkinson’s disease or other neurological disorders.

Senior man suffering from hand tremors due to Parkinson's disease
Senior man suffering from hand tremors due to Parkinson’s disease (© Pixel-Shot –

Dr. Pankaj Pasricha from Mayo Clinic Arizona, the lead author of the study, states that both methods identified four gastrointestinal conditions that increased the likelihood of a Parkinson’s diagnosis. Specifically, gastroparesis (delayed stomach emptying), dysphagia (difficulty swallowing), and constipation all showed more than double the risk of Parkinson’s within five years before diagnosis. On the other hand, IBS without diarrhea correlated with a 17-percent increased risk.

Interestingly, the researchers observed that appendix removal appeared to offer some protective effects, sparking questions about its potential influence on the disease’s development. Neither inflammatory bowel disease nor vagotomy (partial or full removal of the vagus nerve, often for treating peptic ulcers) displayed a heightened risk association.

Dr. Pasricha notes that other gastrointestinal conditions, like functional dyspepsia (a stomach discomfort or fullness without a clear cause), IBS with diarrhea, and diarrhea coupled with incontinence, were more frequently seen in individuals who eventually developed Parkinson’s. However, these conditions were also prevalent prior to the onset of Alzheimer’s or cerebrovascular diseases.

Emphasizing the nature of the research, Dr. Pasricha highlights that this was an observational study, meaning it couldn’t definitively determine causality.

“This study is the first to establish substantial observational evidence that the clinical diagnosis of not only constipation, but also dysphagia, gastroparesis and irritable bowel syndrome without diarrhea might specifically predict the development of Parkinson’s disease,” the study authors conclude in a media release.

“These findings warrant alertness for [gastrointestinal] syndromes in patients at higher risk for Parkinson’s disease and highlight the need for further investigation of [gastrointestinal] precedents in Alzheimer’s disease and cerebrovascular disease.”

The findings are published in the online journal Gut.

South West News Service writer Stephen Beech contributed to this report.

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