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Gastric issues in Parkinson's Disease

30 Nov 2021 15:00 - 16:00

Please note that all session and slide content are the views of the Speakers, not the Parkinson’s Academy. The content of the recording is the speaker’s personal opinion at the time of recording. Due to the ever changing situation, advice given at the time of recording is subject to change.


In addition to the motor symptoms in Parkinson’s disease the condition can also cause multiple problems along the gastrointestinal system. Gastrointestinal symptoms are known to affect nutritional status, similarly Parkinson’s medication can cause nausea, vomiting and constipation all of which can affect nutritional status.

The presentations aim to:

  • Provide a review of gastrointestinal dysfunction in Parkinson’s
  • Provide understanding of the interplay between Parkinson’s, comorbidities and nutritional status
  • Highlight the common problems that may result in the gastrointestinal system in Parkinson’s
  • Through case study presentation highlight the interventional strategies that may improve symptoms, augment care and enhance quality of life.

CPD accreditation

'Gastric issues in Parkinson's Disease' has been approved by the Federation of the Royal Colleges of Physicians of the United Kingdom for 1 category 1 (external) CPD credit(s). Please note CPD Federation approval does not include satellite symposia sessions. To claim the credit please email

Dr Fiona Lithander & Dr Mícheál Ó Breasail - Presentation slides

Richelle Flanagan - Presentation slides

Lynne Osborne - Presentation slides


As the prevalence of Parkinson’s disease (PD) continues to increase, it is ever more important to understand the interplay between the condition, its comorbidities, and nutritional status.

Dr Fiona Lithander explained that anosmia, or the absence of smell, can affect up to 90% of people with PD. Ageusia, or the absence of taste, is a less common but important symptom, reported in up to 27% of people with PD.

“These two factors alone can adversely affect dietary intake,” she said, adding this can impact on weight and nutritional status.

Dysphagia can also negatively impact on nutritional status, can affect quality of life, and is a risk factor for adverse outcomes such as pneumonia, she added.

Other factors that can impact on a person with PD’s ability to eat include xerostomia and hypersalivation, dystonia, which can be linked to taste abnormalities, and oral/facial pain.

“Moreover, difficulties in ingesting food may impair the intake of specific nutrients, such as vitamin D and calcium, subsequently increasing the risk of fracture,” said Fiona.

Delayed gastric emptying is common in PD, due to poor motility. This can result in nausea, bloating, and early satiety, all of which can reduce appetite and dietary intake, increases the risk of malnutrition. In addition, motility issues can also affect dopaminergic medication absorption and hence worsen motor control.

Many people with PD also have an abnormal gut microbiome, with, when compared to healthy controls, an overabundance of species associated with GI symptoms, including constipation.

Fiona said: “A number of hypothesis has been proposed around the effect that these bacteria in the gut may have on nutritional status. These include decreased absorption of vitamin D, which may increase the risk of fractures.”

Constipation is linked to worse outcomes, including earlier onset of dementia, and is a risk factor for malnutrition, she added.

“There's no doubt that gastrointestinal dysfunction is common in people with Parkinson's and many factors can negatively impact nutritional status.

“Further research may contribute to the development of interventional strategies to improve symptoms, augment care, and, importantly, enhance quality of life for patients living with this complex neurodegenerative disease,” concluded Fiona.

More research needed

Nutrition can have “quite a bearing” on weight, bone mass, and muscle mass, and the GI issues associated with the disease can impact on nutritional intake, said Dr Mícheál Ó Breasail.

Monitoring malnutrition, then, is essential, he went on, pointing to guidance published this year by the British Dietetic Association (BDA) and Parkinson’s Disease UK (PDUK).

“It highlights the importance of continuously monitoring the risk of malnutrition and body weight across the spectrum of disease, starting when people are diagnosed, and moving all the way as their condition progresses,” said Mícheál.

This includes monitoring motor symptoms and worsening dyskinesia, as well as preventing and reversing weight loss, he added.

Malnutrition is one of the leading risk factors for sarcopenia, though, due in large part to differing definitions in the literature, its prevalence in PD is still unclear.

The connection between PD and bone health is also complex because of a “series of fraudulent papers which have since been retracted”.

Mícheál said: “It does appear clear, however, that people living with Parkinson's are at risk of having lower bone mineral density than controls, and there does appear to be an increased risk of fracture in people with Parkinson's, particularly at the hip.”

Concluding his “whistle-stop tour” of the importance of weight, bone health, and muscle mass in PD, Mícheál said more research was needed, both in terms of “synthesising the data that have been published”, but also in terms of new work to “establish greater certainty around the prevalence of these comorbidities in Parkinson's”.

Managing gastric issues

Richelle Flanagan described the complexities of managing constipation in PD, saying healthcare professionals needed to look at every patient individually,

“PD can cause constipation, but constipation is also a prodromal symptom of PD. Levodopa can improve constipation, but levodopa can worsen constipation.

“Pain is associated with worsening constipation, but pain medication can worsen constipation. Pain can reduce one's ability to exercise, but less exercise has been shown to worsen constipation,” she said.

Comorbidities, such as celiac disease and irritable bowel syndrome, as well as factor including sex, ethnicity, and age, also all play a role.

In terms of management, Richelle said that people should be getting between 25g and 30g of fibre a day. This should be a mix of soluble fibre, or wholegrains, and insoluble fibre, such as fruit and vegetables. Dehydration can worsen constipation, so drinking plenty of fluids is essential.

“We shouldn’t have a fear of using laxatives, but we want to start with the first line, which is fibre and water,” she said.

Richelle went on to say that many teams were “under serving the PD community” by not routinely assign swallowing from diagnosis onwards – many people, she said, do not realise they have a problem.

“If the levodopa isn’t even getting past the back of the throat and down into the stomach, they are at a deficit to start with in terms of improving their GI function,” she said.

In terms of meal composition, teams should advise against meals that are high in fat and protein. These elements can delay gastric emptying further, slowing the medication’s route from the stomach, and into to the bloodstream.

She added: “Eating a diet rich in plant-based foods is associated with healthier gut bacteria and a healthier movement of the bowel.”

Case study

Lynne Osborne shared a patient case study to help illustrate the considerations of constipation and GI symptom management.

Brian, 77, was diagnosed with PD in 2014, and was referred to Lynne for a non-oral therapy opinion in March 2021. He had a history of unpredictable fluctuations and severe off periods during which his medication didn’t work. He described feeling “locked in” and unable to speak, and he needed his wife to help with everyday activities.

During a video assessment, Lynn discovered that Brian had severe constipation, did not always take his medication on time, and that he usually took it with food. He had poor fluid intake and diet, and was not on laxatives.

Lynne asked Brian to use a Parkinson’s kinetograph (PKG), a watch-like device which monitors symptoms from a motor perspective, allowing teams to optimise dosing times. It showed that his bradykinesia took a considerable time to improve after Brian took his medication.

“This showed us he had quite prominent absorption problems which could be contributing to his deteriorating motor function and his poor control of his Parkinson's symptoms,” said Lynne.

Brian was given a CT enema, help with increasing his fluids, and laxatives. The team also suggested he take his Madopar at least 30 minutes before eating, and offered adherence advice.

To aid absorption, they also changed his oral agonist medication to a Rotigotine patch, and the Madopar standard release capsule to a dispersible formulation.

When the PKG was repeated three months later, there was a considerable improvement in Parkinson’s control and quality of life.


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