Management of Constipation in Parkinson's Disease

Maintenance Regimen

The American Gastroenterological Association recommends starting with polyethylene glycol (PEG) 17g once daily as the primary maintenance laxative for Parkinson's disease constipation, due to its superior efficacy and tolerability 1, 4
Adding fermented milk containing probiotics and prebiotic fiber daily has Level B evidence, demonstrating increased complete bowel movements, improved stool consistency, and reduced laxative dependence in Parkinson's patients 1, 2, 5, 6
Ensuring adequate water intake (aim for >900 ml/day) is crucial, as Parkinson's patients characteristically have reduced water consumption that precedes and correlates with constipation severity 1
The European Society for Neurogastroenterology and Motility recommends avoiding bulk-forming laxatives like psyllium if the patient has reduced mobility or inadequate fluid intake due to mechanical obstruction risk 4, 7, 1

The National Comprehensive Cancer Network recommends administering bisacodyl suppository 10mg rectally as the first rescue intervention if no bowel movement occurs within 2 days 8, 3
If the suppository fails, proceeding to fleet enema (sodium phosphate enema) once daily is recommended, with continuation for up to 3 days if needed for complete cleanout 8
The American Geriatrics Society suggests that isotonic saline enemas are preferable to sodium phosphate enemas in elderly patients due to potential adverse effects 4

Constipation in Parkinson's results from enteric nervous system neurodegeneration, not just medication effects, according to the International Parkinson and Movement Disorder Society 1, 2, 5, 6
Defecatory dysfunction may involve both slow colonic transit AND pelvic floor dyssynergia, as noted by the European Society for Neurogastroenterology and Motility 1, 2, 6
The same treatment algorithm used for idiopathic chronic constipation applies to Parkinson's patients, as stated by the American Gastroenterological Association 1, 2, 6

Before any enema or suppository use, exclude neutropenia or thrombocytopenia, recent colorectal/gynecological surgery or anal trauma, paralytic ileus or intestinal obstruction, severe colitis or abdominal inflammation, and recent pelvic radiotherapy, as recommended by the American Society of Clinical Oncology 4, 3