Dysphagia (difficulty in swallowing) is a common problem in people with Parkinson's Disease. In order to assess the prevalence of dysphagia and other related symptoms, people with Parkinson's Disease presenting with dysphagia, odynophagia, heartburn, regurgitation, chest pain, and weight loss underwent evaluation using high-resolution manometry (HRM).
Most people with Parkinson's Disease (62%) experienced dysphagia (difficult swallowing), which probably contributed to weight loss in 41% of people because they were unable to eat as much. The prevalence of other symptoms was heartburn (37%), regurgitation (31%), chest pain (28%), and odynophagia (painful swallowing) (6%). Problems in the esophagus were also common.
The esophagus is through which food passes from the mouth to the stomach. The most common problems were : failure by the esophagus to contract properly (ineffective esophageal peristalsis) (55%), fragmented contraction in the esophagus (fragmented peristalsis) (48%), spasms in the esophagus (DES - diffuse esophageal spasm) (48%), and obstruction of the exit of the esophagus to the stomach (EGJ outflow obstruction) (39%). Each of these causes digestive problems.
Reference : Diseases of the Esophagus  30 (4) : 1-6 (A.Su, R.Gandhy, C.Barlow, G.Triadafilopoulos) Complete abstract : http://www.ncbi.nlm.nih.gov/pubmed/28375482