Parkinson Disease and Constipation

Erica Vitek, MOT, OTR, BCB-PMD, PRPC has attended extensive post-graduate rehabilitation education in the area of Parkinson disease and exercise. She is certified in LSVT (Lee Silverman Voice Treatment) BIG and is a trained PWR! (Parkinson Wellness Recovery) provider, both focusing on intensive, amplitude, and neuroplasticity-based exercise programs for people with Parkinson disease. Erica has taken a special interest in the unique pelvic floor, bladder, bowel, and sexual health issues experienced by individuals diagnosed with Parkinson disease. You can learn more about this topic in Erica's course, Parkinson Disease and Pelvic Rehabilitation, scheduled for July 23-24, 2021.

Parkinson disease (PD) non-motor symptoms can be even more impactful on quality of life than the cardinal motor symptoms most are familiar with, bradykinesia, rigidity, tremor, and postural instability. The list of non-motor symptoms is extensive affecting many body systems including cognitive, sensory, and autonomic.

Constipation is one of the most common autonomic non-motor symptoms experienced by people with Parkinson disease with studies showing 20-89% prevalence (1). As the disease progresses, individuals are more likely to experience symptoms that suggest a strong relationship between neurodegeneration and bowel dysfunction, such as, decreased frequency of bowel movements, difficulty expelling stool, and diarrhea (2). Constipation has also been hypothesized to be an early indicator for the development of Parkinson disease, and there is ongoing research in this area. It has yet to be shown that constipation is specific enough to predict the development of PD.  

Developing an understanding of Parkinson disease constipation and how it differs from other individuals with constipation can have a strong impact on our recommended pelvic rehabilitation plans of care. In a study published by Zhang, M. et al., 2021, they looked at the characteristics of Parkinson disease with constipation (PDC) compared to functional constipation (FC). Functional constipation is generally defined as difficult, infrequent, or incomplete defecations (3). One of the main findings in this study was a significant difference between the groups when looking at resting rectal and anal canal pressures. In the PDC group, resting rectal and anal pressures were significantly lower. These resting pressures are mainly controlled by the internal anal sphincter resting tension which is supported by the autonomic nervous system. This leads the researchers to speculate there may be autonomic nervous system neuropathy in people with PD

They then looked at simulated defecation, which also showed that the PDC group had significantly lower rectal defecation pressure and a lower anal relaxation rate. Since rectal pressures during defecation assist in effective anal relaxation, the researchers state, “a coordinated movement disorder results” and that people with PD may have “pelvic floor cooperative motion disorder” (1). Additionally, the researchers noted that abnormal abdominal pressure is another main contributing factor to the low rectal defecatory pressure in PDC. Abdominal pressure is a key factor in driving complete and efficient rectal defecation. This is also a finding in numerous other studies in the literature unique in PDC.  

The results of Zhang, M. et al., 2021 reveal the need for pelvic health practitioners to help train coordinated defecation efforts in people with Parkinson disease. In my course, Parkinson disease and Pelvic Rehab, we will have an in-depth discussion about how training defecatory dynamics is different in people with PD. Muscle training principles in this population are very unique. Understanding the underlying causal factors of dysfunction will have a significant impact when helping patients with Parkinson disease manage constipation.

1. Zhang, M., Yang, S., Li, X. C., Zhu, H. M., Peng, D., Li, B. Y., ... & Tian, C. (2021). Study on the characteristics of intestinal motility of constipation in patients with Parkinson's disease. World Journal of Gastroenterology, 27(11), 1055.
2. Sakakibara, R. (2021). Gastrointestinal dysfunction in movement disorders. Neurological Sciences, 1-11.
3. Lacy, B. E., Mearin, F., Chang, L., Chey, W. D., Lembo, A. J., Simren, M., & Spiller, R. (2016). Bowel disorders.Gastroenterology 150 (6), 1393-1407.