Gastrointestinal Dysfunction in Parkinson’s Disease: Neuro-Gastroenterology Perspectives on a Multifaceted Problem

Abstract

Patients with Parkinson’s disease (PD) face a multitude of gastrointestinal (GI) symptoms, including nausea, bloating, reduced bowel movements, and difficulties with defecation. These symptoms are common and may accumulate during the course of PD but are often under-recognized and challenging to manage. Objective testing can be burdensome to patients and does not correlate well with symptoms. Effective treatment options are limited. Evidence is often based on studies in the general population, and specific evidence in PD is scarce. Upper GI dysfunction may also interfere with the pharmacological treatment of PD motor symptoms, which poses significant management challenges. Several new less invasive assessment tools and novel treatment options have emerged in recent years. The current review provides an overview and a practical approach to recognizing and diagnosing common upper and lower GI problems in PD, e.g., dyspepsia, gastroparesis, small bowel dysfunction, chronic constipation, and defecatory dysfunction. Management aspects are discussed based on the latest evidence from the PD and general populations, with insights for future research pertaining to GI dysfunction in PD.

Associations between gut microbiota characteristics and non‐motor symptoms following pharmacological and surgical treatments in Parkinson's disease patients

“…Constipation, difficulty with defecation, and fullness in the upper abdomen are common gastrointestinal symptoms often seen in patients with PD 65 . These symptoms are thought to be caused by a combination of factors, including impaired motor function in the digestive tract, reduced secretion of digestive enzymes, and changes in the gut microbiome due to the side effects of levodopa treatment.…”

Alpha Synuclein Toxicity and Non-motor Parkinson’s

“…Furthermore, PD patients experience a more widespread onset of lifelong GI symptoms and constipation is widely recognized as one of the most prevalent NMS of PD. Intestinal microbiome also plays a role in the bidirectional communication between the brain and the gut that has emerged as a significant aspect of PD pathology [193][194][195].…”