Please assess the completion status of the following clinical trial:

Trial Title: A Clinical Standardization Study of the Preferred Acupuncture Treatment Protocol to Treat Functional Constipation

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE2
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion Criteria:~* meeting the diagnosis of Rome III criteria;~* aged from 18 to 75 years old;~* no use of medicine for constipation about 2 weeks before the enrollment, no acupuncture treatment for constipation in the previous 3 months, and never joined any other trial in progress in the previous 3 months;~* volunteered to join this trial and signed the informed consent form~Exclusion Criteria:~* irritable bowel syndrome, organic constipation or secondary constipation caused by endocrine, metabolic, nervous, postoperative diseases, or by drugs;~* constipation with serious cardiovascular, hepatic or renal diseases, cognitive dysfunction, aphasia, mental disorders, or illness which affects the cooperation for examination and treatment;~* women in gestation or lactation period;~* abdominal aortic aneurysm or hepatosplenomegaly, etc.;~* blood coagulation disorders or using anticoagulants regularly such as Warfarin and Heparin;~* cardiac pacemaker carrier.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 75 Years
- Healthy Volunteers: f

Study Arms:
- deep needling group (Type: EXPERIMENTAL): Acupoints of bilateral Tianshu (ST25), which were located according to WHO Standardized Acupuncture Points Location, were used. After sterilizing the skin, needles of the size of 0.35×0.75mm were inserted into ST25 vertically and slowly without manipulation for about 20\~60mm until piercing into the muscle layer. Paired alligator clips of the electric acupuncture (EA) apparatus were attached transversely to the needle holders of bilateral ST25. EA stimulation lasted for 30 minutes with a dilatational wave of 2/15Hz and current intensity of 0.1\~1mA. Participant's abdominal muscle twitching mildly showed the proper dose. Patients were treated once a day, five times a week for continuous 4 weeks.
- lactulose group (Type: ACTIVE_COMPARATOR): Lactulose Oral Solution was taken orally at the dose of 20\~30ml once every morning after breakfast for continuous 4 weeks. Patients should take lactulose for another 3 months if no severe adverse effect was showed.
- shallow needling group (Type: ACTIVE_COMPARATOR): Bilateral ST25, the same acupoints as deep needling group, were used. After skin disinfection, needles of the size of 0.30×25mm penetrated the skin uprightly for about 5\~9mm into the fat layer without manipulation. The usage of EA apparatus and treatment course were the same as deep needling group.

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