Please assess the completion status of the following clinical trial:

Trial Title: Lubiprostone as a Treatment for Constipation in Parkinson's Disease

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: None
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~1. Age 50-85 years~2. Diagnosis of Parkinson's disease~3. Constipation as defined by the Rome III committee~4. BSFS of more or equal to 1 and less or equal to 3~5. Normal colonoscopy in the last 5 years( normal defined as absence of obstructive lesions in the colon)~6. All women subjects will be post menopausal or surgically sterile.~Exclusion Criteria:~1. Known hypersensitivity reaction to Amitiza ( Lubiprostone)~2. Known significant adverse effects to previous treatment with Lubiprostone which include; new or worsening abdominal pain, severe diarrhea, nausea, vomiting, and severe headache.~3. Renal dysfunction with creatinine clearance less than 15 ml/min~4. Abnormal liver enzymes or history of chronic liver disorder~5. History of bowel obstruction, , or abdominal adhesions .~6. Abnormal Colonoscopy ( obstructive lesions within the colon)~7. Inability to give informed consent

- Gender: ALL
- Minimum Age: 50 Years
- Maximum Age: 85 Years
- Healthy Volunteers: f

Study Arms:
- Patients (Type: EXPERIMENTAL): None

Based on this trial design, predict the completion outcome and termination type (if applicable).