In a recent study we identified abnormal salivation, dysphagia, nausea, constipation, and defecatory dysfunction as those gastrointestinal (GI) symptoms associated with Parkinson disease (PD) and characterized their relationship to PD severity and therapy. In this study, we re-evaluated these symptoms and their relationship to parameters of PD 18 months later. Sixty-six percent of the original participants responded. Over the 18 months, 68% of originally untreated PD subjects commenced anti-PD therapy. Abnormal salivation, dysphagia, nausea, constipation, and defecatory dysfunction were again identified as those GI symptoms more common in PD. Constipation increased both in severity and frequency. Comparison of GI symptom scores and parameters of PD dysfunction failed to reveal significant progression of either GI symptomatology or PD dysfunction, or the development of new GI symptoms over the 18-month period. This study validates our GI dysfunction assessment system and confirms abnormal salivation, dysphagia, nausea, constipation, and defecatory function as those GI symptoms truly associated with PD. A direct relationship between PD and its related GI symptoms is again supported.