Characterization of Gastrointestinal Symptom Type and Severity in Parkinson's Disease: A Case-Control Study in an Australian Cohort.

Background: While constipation is a well-known non-motor symptom which may precede the onset of the classical motor symptoms of PD, there have been few comprehensive studies of gastrointestinal (GI) symptoms in people with PD (PwP).

Objectives: To investigate the spectrum of GI symptoms in an Australian PwP cohort and their relationship to use of anti-parkinsonian medications dietary habits and smoking.

Methods: The prevalence and severity of GI symptoms were compared in a group of 163 PwP and 113 healthy control subjects using the Gastrointestinal Symptom Rating Scale (GSRS). Corrected linear regression models were used to determine differences between PwP and controls, and to investigate the influence of different classes of anti-Parkinsonian medications.

Results: PwP reported a greater frequency of constipation and GI-associated illnesses when compared to healthy controls. Total GSRS scores ( < 0.0001), upper GI symptoms ( < 0.0001), and hypoactive GI Symptoms ( < 0.0001) were all significantly greater in the PD cohort than controls. Further analyses revealed a positive association between the use of anti-Parkinsonian medications and total GSRS scores ( < 0.001), as well as upper GI symptoms ( < 0.001) and hypoactive GI function ( < 0.001).

Conclusions: This study illustrates the frequency and array of GI symptoms in a large PD cohort. The findings indicate that anti-parkinsonian medications play an important role in the presentation and development of GI symptoms.