Evaluation of the Efficacy and Safety of Fecal Microbiota Transplantation for Constipation in Parkinson's Disease

This study tests fecal microbiota transplantation (FMT) — a procedure that transfers healthy gut bacteria from a donor — to help relieve constipation in people with Parkinson's disease. Parkinson's patients frequently experience severe, ongoing constipation that is hard to treat with standard laxatives. **You may be eligible if...** - You are between 40 and 75 years old with a diagnosis of Parkinson's disease (Hoehn-Yahr stage 1–3, meaning mild to moderate) - You have had chronic constipation symptoms for at least 6 months (e.g., straining, hard stools, fewer than 3 bowel movements per week) - Your Parkinson's medications have been stable for at least 1 month **You may NOT be eligible if...** - You have a Parkinson's-plus syndrome (a related but different condition) - You have had a stroke, brain injury, or epilepsy - You have had abdominal surgery other than appendectomy, gallbladder removal, C-section, or hysterectomy - You are pregnant, planning pregnancy, or breastfeeding - You have an immune deficiency or take immune-suppressing medications Talk to your doctor to see if this trial is right for you.