Please assess the completion status of the following clinical trial:

Trial Title: Effects of Lubiprostone on Gastric Function in Patients With Chronic Idiopathic Constipation

Study Design Characteristics:
- Allocation: None
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: HEALTH_SERVICES_RESEARCH
- Time Perspective: None
- Masking: NONE
- Phase: PHASE4
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~* chronic idiopathic constipation~Exclusion Criteria:~* medications that slow gastrointestinal (GI) motility~* prior surgery to the GI tract

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Treatment (Type: EXPERIMENTAL): 24 micrograms of lubiprostone twice daily for one week.

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